bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) Ingenious Nanomaterials for Ultrasensitive ECL
Authors: Valenti Giovanni , Rebeccani Sara , Zanut Alessandra , Marcaccio Massimo , Paolucci Francesco
Published: July 2022

The impact of nanotechnology and nanosystems on analytical science is hardly overlooked. In the search for ever-increasing sensitivity in biomedical sensors, nanoparticles have been playing a unique role as, e.g., ultrabright labels in clinical analysis (markers, tumor cells, and pharmaceuticals) and in the detection of pathogenic microorganisms, toxic agents, and pesticides in the environmental field and food products. Coupling such nanosystems with electrochemiluminescence (ECL), which naturally brings improved signal-to-noise ratio compared to photoluminescence, with minimized effects due to light scattering and luminescence background, has brought about new systems and strategies for analytes determination, even in very complex matrices, such as urine, blood or lysate.

Among the several nanosystems, dye-doped silica nanoparticles (DDSNs) have proved as very promising and versatile nanomaterials in ECL-based bioanalytical platforms. The increase of the number of complexes active in the generation of the ECL signals together with an even larger increase in the signal stability, represents in fact a promising strategy towards ultrasensitive ECL.

Approaches based on ECL generation on the nanoscale using luminophore-reporter-modified DNA-based nanoswitches (i.e., molecular beacon) has been additionally investigated and, in this context, the development of innovative amplification-free detection methods represents a significant breakthrough compared to existing PCR-based methodologies, allowing the integration of nucleic acid detection on portable and low-cost sensor devices, and enabling the massive diagnostic screening.
(Digital Presentation) Simultaneous and Real-Time Electrochemical Detection of Multiple Biomarkers in a Microfluidic Chip
Authors: Tuladhar Pragun R , Miller Dusty R , Xu Kaixuan , Cliffel David E
Published: July 2022

Dysregulations in metabolic and physiological cellular processes are generally accompanied by changes in concentration profiles of multiple biomarkers. Measuring dynamic changes in concentrations of several affected biomarkers can enhance our comprehension of the underlying disease pathophysiology and/or mechanisms of cytotoxicity. Most analytical detection techniques require samples to be obtained at pre-defined times for offline analysis. However, the inadequate temporal resolution of these methods can lead to key biological events that occur at shorter timescales, being overlooked. Electrochemical biosensors are relatively simple, cost-effective detection techniques that have been used extensively for continuous analyte monitoring, and more recently, for sensing multiple analytes. We describe the design and functionality of a novel electrochemical detection platform, comprising a screen-printed Pt electrode array, a microfluidic chip, and an automated pump and valve system, capable of quantitatively detecting up to eight analytes. As a proof of concept, we show the simultaneous, sensitive, and selective amperometric detection of four essential biomarkers- glucose, lactate, glutamate, and acetylcholine, in real time. We also demonstrate the biological application of this platform by continuously monitoring exocytotic glutamate release from human induced pluripotent stem cell-derived neuronal cultures over time. Excessive accumulation of glutamate in the synaptic cleft leads to prolonged stimulation of glutamate receptors on neurons, triggering a cascade of neurotoxic events that ultimately results in loss of neuronal function and cell death. The results suggest that our multianalyte electrochemical sensor platform can be coupled with more complex biological systems such as in vitro organotypic models, for the accurate monitoring of biomarker changes during adverse events like acute neurotoxicity and microbial infection.
Application of Single-Stranded DNA and PNA Probes for Electrochemical Detection of miRNA 141
Authors: Jarczewska Marta , Bojarski Wiktor , Majewska Aleksandra , Mieczkowska Magdalena , Drozd Marcin , Ziolkowski Robert , Malinowska Elżbieta
Published: July 2022

miRNA are known as short RNA molecules that usually consist of 18 – 25 nucleotides and are considered as posttranscriptional regulators of gene expression occurring in plants and animals [1]. Over 60% of all genes which encode proteins are controlled by miRNA [2]. miRNA is engaged in various processes including differentiation, proliferation and apoptosis as well as inflammation. Hence, they might be considered as potential biomarkers of diseases such as cancer, neurodegenerative and cardiovascular [3]. A huge challenge is the actual detection of miRNA because of their short length, low concentration and matrix interferences. The miRNA analysis can be performed with the following techniques such as real-time PCR, northern blotting and microarray [4-6]. However, the above mentioned techniques are rather sophisticated and are costly. An alternative could be the application of electrochemical techniques which are characterized with low detection limits, possibility of miniaturization and high sensitivity. In such a case miRNA could be detected using biosensors containing receptor layers formed of single-stranded DNA or PNA.

Herein, we present the studies on the development of ssDNA/PNA – based receptor layers for the electrochemical analysis of miRNA 141, which is a biomarker of pancreatic cancer. Various receptor layers were tested including unlabelled ssDNA, methylene blue-labelled DNA as well as PNA-based. The formation of ssDNA/PNA receptor layer along with its binding to miRNA was confirmed using QCM and SPR techniques. The electrochemical studies revealed that it was not possible to obtain low detection limits for miRNA when MB-labelled ssDNA or PNA molecules were applied. On the contrary, detection limit of 10-4 nM was reached with the application of unlabelled ssDNA molecules. The further analysis showed the possibility of detection of point mutation in ssDNA or miRNA sequence as well as miRNA detection in spiked serum sample.

Bibliography:

[1] D. P. Bartel, Cell 116 (2004) 281–297

[2] A. Krek, D. Grun, M. N. Poy, R. Wolf, L. Rosenberg, E. J. Epstein, P. MacMenamin, I. da Piedade, K. C. Gunsalus, M. Stoffel, N. Rajewsky, N. Nat. Genet. 37 (2005) 495−500.

[3] H. Hwang, J. T. Mendell, Br. J. Cancer 94 (2006) 776–780.

[4] C. Chen, D. A. Ridzon, A. J. Broomer, Z. Zhou, D. H. Lee, J. T. Nguyen, M. Barbisin, N. L. Xu, V. R. Mahuvakar, M. R. Andersen, K. Q. Lao, K. J. Livak, K. J.Guegler, Nucleic Acids Res. 33 (2005) e179

[5] A. Valoczi, C. Hornyik, N. Varga, J. Burgyan, S. Kauppinen, Z. Havelda, Nucleic Acids Res. 32 (2004) e175

[6] A. M. Krichevsky, K. S. King, C. P. Donahue, K. Khrapko, K. S.Kosik, RNA 9 (2003) 1274−1281.
(Digital Presentation) Electrocatalytic Cortisol Tracing Smart Patch
Authors: Yeasmin Sanjida , WU Bo , Ullah Ahasan , Zhang Boxin , Cheng Li-Jing
Published: July 2022

Rapid and continuous tracking of the stress hormone cortisol's circadian rhythm is vital for diagnosing diseases related to chronic stress and adrenal gland disorders [1]. Commercial cortisol sensors relying on labeled enzyme and antibodies suffer from limited stability, lengthy reaction time, and cross-reactivity with analogous molecules [2]. To address these issues, we developed an electrocatalytic sensor using phthalocyanine (Pc) doped molecularly imprinted polymer (MIP) modified screen-printed electrodes for label-free, reagentless, sensitive, and selective electrochemical detection of cortisol. The sensor was constructed via one-step electropolymerization of conductive prepolymer in the presence of Pc and template cortisol. The controlled release of cortisol templates resulted in an MIP network embedded with Pc catalysts in the vicinity of the cortisol-specific binding cavities. The sensor directly measures the cortisol level by catalysing the reduction reaction of the cortisol captured by the cavities of the MIP. Proof of studies was performed to detect cortisol over a wide concentration range varying from 500 pM to 10 µM with high selectivity against structurally similar hormones. The facile label-free and antibody-free cortisol sensor on a wearable smart patch offers an appealing approach for selective steroid hormone detection at point-of-care testing.

References

[1] Liu, Ye, et al. "Label-Free Sensitive Detection of Steroid Hormone Cortisol Based on Target-Induced Fluorescence Quenching of Quantum Dots." Langmuir 36.27 (2020): 7781-7788.

[2] Manickam, Pandiaraj, et al. "A reusable electrochemical biosensor for monitoring of small molecules (cortisol) using molecularly imprinted polymers." Journal of the Electrochemical Society 164.2 (2016): B54.

Figure 1
(Digital Presentation) La2Zr2O7:Pr3+ Nanoparticles for Luminescence Thermometry Based on a Single Parameter
Authors: Mao Yuanbing , Jahanbazi Forough
Published: July 2022

Luminescence thermometry based on the variation of the fluorescence intensity ratio (FIR) of rare-earth materials has become fascinating owing to their applicability in chemically and electromagnetically harsh environments. Relevant to their practical applicability, a wide temperature sensing range is urgently required for luminescent thermometric materials besides possessing a high relative sensitivity. Herein, we have demonstrated that pyrochlore La2Zr2O7:Pr3+ (LZOP) nanoparticles (NPs) can serve as a promising optical temperature sensing material over a wide temperature range of 620 K. Specifically, we have taken advantage of the intervalence charge transfer state (IVCT) of Pr3+ doping ion for luminescence temperature sensing and confirmed excellent optical thermometric performance from the LZOP NPs in a temperature sensing range of 85-705 K. The thermal sensing here could be measured by exploiting one thermometric parameter, i.e. the FIR between 1D2 → 3H4 and 3P0 → 3H4 transitions of Pr3+, and thus we only need to use one calibration formula for the whole temperature range. A maximum relative sensitivity of > 0.4%·K−1 from 165 to 205 K and a low temperature uncertainty of 1.21 K at 185 K is obtained. Based on the proposed configurational coordinate diagrams, a high-lying IVCT state was demonstrated to be the cause for slow thermal quenching at high temperatures, which broadened the working range of our thermometric sensing materials. This work provides a useful inspiration for exploring appropriate host materials with slow thermal-quenching channels to develop optical thermometric materials over a wide temperature sensing range.

Figure 1
(Digital Presentation) Design and Development of Electrochemical Immunosensor for Brain-Related Protein
Authors: Tabobondung Meaghan , Wallace William , Martic Sanela
Published: July 2022

The process of diagnosis for neurodegenerative diseases relies on the onset of symptoms. However, there is the possibility of detecting these diseases, such as amyotrophic lateral sclerosis (ALS), before progression, which would allow for more treatment. ALS is a neurodegenerative disease that targets the motor system. As the disease progresses, individuals experience a loss in mobility in their appendages and limbs and eventually total muscle paralysis. The development of new diagnostic tools will allow for earlier treatment and provide a greater time frame between diagnosis and disease onset. Early detection of ALS can be achieved by detecting biomarkers associated with the disease, one of which is the TDP-43 protein. Using electrochemistry, miniaturized and portable biosensors which provide rapid response are ideally suited for the point of care applications. Towards this goal, we developed a label-free biosensor based on the electrochemical impedance spectroscopy (EIS). The signal output was the charge transfer resistance (Rct) of the antibody-surface before and after protein exposure. The changes in the Rct values were directly related to the amount of analyte. The sensor used in these experiments was synthesized using a gold disk working electrode, which underwent surface modification, to add TDP-43 antibodies to the surface. After surface modification, the immunosensor optimization was carried out by using several commercial TDP-43 antibodies at various concentrations. The significant changes in Rct values were observed above 100 nM concentration of the protein. This study provides the methodology for fabricating a sensor recognition layer for TDP-43 specifically, but can be easily extended for detection of other disease-related biomarkers.
(Digital Presentation) Electrochemical Sensors for Hydrogen/Deuterium Speciation
Authors: Pallarès Enric Lujan , Hinojo Antonio , Colominas Sergi , Abella Jordi
Published: July 2022

By the end of the century, global energy demand is expected to increase by a factor of three due to population growth. In this context, fossil fuels should not be the main power source due to the elevated environmental cost. Nuclear fusion technology is planned as an alternative to this demand as it is expected to generate large quantities of energy without all the inconveniences of fossil fuels. The most feasible reaction to take place is the fusion between two hydrogen nuclei. Specifically, deuterium and tritium will react releasing helium, neutrons, and large amounts of energy [1].

2H + 3H → 4He + n + 17.59 MeV (1)

In the present work, BaCe0.6Zr0.3Y0.1O3-α electrolyte (BCZY) was used to construct amperometric sensors for hydrogen monitoring. Firstly, BCZY powder was synthesized by the solid-state method and characterized using SEM and XRD. Secondly, it was sintered as a pellet and bound to an alumina tube to construct the electrochemical sensors. Finally, amperometric measurements were performed inside a stainless-steel reactor at 500 °C and applying 0.15 V between electrodes. The response of the sensors was evaluated using hydrogen and deuterium calibration mixtures. The concentration in the WE ranged from 150 to 300 ppm H2 or D2 in Ar. Argon was used in the CE as a cover gas. Finally, measurements with hydrogen and deuterium were compared to determine the isotope effect on the response.

[1] J.Kenneth. Shultis, R.E. Faw, Fundamentals of nuclear science and engineering, Marcel Dekker, 2002.

[2] E.C.C. de Souza, R. Muccillo, Properties and applications of perovskite proton conductors, Materials Research. 13 (2010) 385–394. https://doi.org/10.1590/S1516-14392010000300018.

[3] A. Benes, A. Molinari, R. Witte, R. Kruk, J. Brötz, R. Chellali, H. Hahn, O. Clemens, Proton Conduction in Grain-Boundary-Free Oxygen-Deficient BaFeO2.5+δ Thin Films, Materials. 11 (2017) 52. https://doi.org/10.3390/ma11010052.

[4] A. Hinojo, I. Soriano, J. Abellà, S. Colominas, Evaluation of High-Temperature Hydrogen Sensors Based on BaCe0.6Zr0.3Y0.1O3-α and Sr(Ce0.9Zr0.1)0.95Yb0.05O3-α Perovskites for Industrial Applications, Sensors. 20 (2020) 7258. https://doi.org/10.3390/s20247258.
Co-Determination of the Kinetics and Stoichiometry of Electrochemical Ion Transfer at the Liquid-Liquid Interface
Authors: D'Antona Nicholas R , Kempler Paul A. , Boettcher Shannon W.
Published: July 2022

The desolvation of ions at electrochemical interfaces is widely accepted as being the rate limiting step to charge transfer in devices such as ion-intercalation batteries and electrolyzers. While activation energies can be obtained for processes like ion intercalation, the kinetics and mechanism of desolvation remain elusive because they are often convoluted with resistances arising from complex interfacial chemistries. Here I present the use of a biphasic microfluidic electrochemical cell to simultaneously study the kinetics and stoichiometry of tetrabutylammonium (TBA) ion transfer at the interface between two immiscible electrolyte solutions (ITIES). Ion transfer at the ITIES allows one to mostly eliminate the variable of complex interfacial chemistry in the process of desolvation, and with our flow cell geometry we can separate the two phases after ion transfer to measure reaction products via quantitative nuclear magnetic resonance spectroscopy (qNMR). Thus, our novel microfluidic platform for studying electrochemical ion transfer allows us to correlate desolvation kinetics with ion-solvent shell identity, and eventually inform the design of ion transfer mediators/catalysts for the improvement of energy storage technology.

Figure 1
Performance Estimation Method of Li-Ion Starting-Lighting-Ignition Batteries of Electric Vehicle through Lab-Scale Pouch Cell Experiment
Authors: Oh Hyeseong , Gil Naeun , Kim Daeun , Jeong Kyeong-Min
Published: July 2022

CCA (cold-cranking amps) is used as one of the standards to define the power of a SLI (starting-lighting-ignition) battery of electric vehicles (EVs) by applying a large discharge current for a short time. It is easier to start an engine at a high temperature than a low temperature, so tests are usually conducted at a low temperature to meet the demands of users. However, in a large cell, the internal temperature of the cell rises due to the heat of the cell when a large current is applied. This phenomenon can increase the overall cell power performance because it has the effect of reducing ohmic overvoltage and improving electrode kinetics. Therefore, it is difficult to distinguish the effect of the temperature rise and applied current on the voltage curve during the consecutive pulse discharge.

In this study, three times of 10 C discharge current pulse (~ 7 mA/cm2 in this study) is applied on a cell for 30 seconds, with rest periods of 600s, 30s included between each pulse. Evaluations were conducted from -18 ℃ to 50 ℃, with a LiFePO4/graphite lab-scale pouch cell rather than an actual large cell. Therefore, the temperature of the cell remained constant under the evaluation conditions in which heat generation is almost zero, so the voltage curves can be interpreted by excluding the effect of the temperature rise of a cell. Based on these experimental results, voltage curves were simulated depending on each internal resistance that related to Joule heating of the actual large cell. It is possible to predict the performance and degree of temperature rise of large cells. Also, this study proposes an effective and economical method to distinguish the effect of the temperature rise of the large cell and the applied current by using a lab-scale pouch cell with controlled temperature.
Understanding Behavior of Cathode Active Materials with Different Particle Sizes in Mixed Electrode through Current Distribution Measurement
Authors: Gil Naeun , Jeong Kyeong-Min
Published: July 2022

The performance of a lithium-ion battery can be improved by mixing two or more kinds of cathode active materials in one electrode. In particular, energy density can be increased by mixing active materials having different particle sizes because the electrode can be filled with more active materials. As the performance of a battery is determined by the combination of the properties of the material itself and the electrode design conditions, it is most important to understand the characteristics of the material and the electrode independently. However, since the potential in a mixed electrode is measured as the mixed potential of each active material, it is not easy to identify how each active material behaves electrochemically under the current load condition.

In this experiment, we attempted to separate only the effects of active materials while minimizing the influence of the electrode density, which affects the mass transfer in the porous electrode. For this purpose, two electrodes consisting of small and large particles are placed in one pouch cell and connected in parallel with Li metal as a counter electrode. By measuring the current flowing through each electrode individually, we observed how small and large particles work in mixed electrode.

Since the influence of mass transfer inside the electrode was minimized, it was assumed that the mass transfer did not affect the currents divided into each electrode. Thus, current flowing to each electrode is determined by the relative contributions of charge transfer and solid diffusion kinetics. Large particles have smaller charge transfer resistance and slower solid diffusion than small particles. If rate-liming step is charge transfer, more currents flow to large particles by small charge transfer resistance. If rate-limiting step is solid diffusion, more currents flow to small particles due to the fast diffusion in active materials. Through this experiment, we could analyze the behavior of active materials having different particle sizes in mixed electrode by detecting the current respectively.
Study of Improving the Thermal Stability of Ceramic Coated Separator Via Chemical Crosslinking between Ceramic Particles and Polymeric Binders
Authors: Roh Youngjoon , Jin Dahee , Byun Seoungwoo , Ryou Myung-Hyun , Lee Yong Min
Published: July 2022

Lithium-ion batteries (LIBs) are used in everyday applications such as portable electronics and electric vehicles (EVs) in our daily life. In large-scale batteries such as EVs, high energy density has been developed to secure longer mileage with one charge. Securing battery safety becomes extremely challenging as densifying the cell energy and increasing the battery. The safety of batteries must be guaranteed from the cell to the module, the pack, and the system, and it must not be ignored at every step. The separator is highlighted at the cell level as it plays an essential part in safety. To guarantee the safety of large-scale LIBs, it is essential to employ a ceramic-coated separator (CCS). To secure thermal stability using CCSs, the certain thickness of ceramic coating layer (CCL) is required. In contrast, the thicker CCL can act as a resistive layer in the cell, and in the worst case, the ceramic that has fallen off the CCS surface can act as a side reactant in the cell. However, if the CCL is thin, the desired thermal stability may not be obtained. The key technology is to improve adhesion while reducing the thickness of the CCL.

For this purpose, polydopamine nano layer is preliminary introduced on the surface of ceramic particles via simple solution polymerization. Then, poly(acrylic acid) binder, which can react with amine groups in polydopamine, is chosen for aqueous ceramic coating slurry. Thus, this combination can make several crosslinking points within CCL, which lead to higher adhesion within the CCL after electrolyte impregnation. As a result, the adhesion within the CCL of cross-linked CCS is increased by 70% compared to the non-crosslinked CCS. Furthermore, the adhesion does not decrease when impregnated with the electrolyte. Also, cross-linked CCS showed better shrinkage property than commercialized CCS with the same composition because the cross-linked CCS did not shrink even when exposed for 1 hour at a high temperature of 160 °C. From this study, with crosslinking reaction within coating layer, it is possible to improving heat resistance and physical properties of separator without increasing thickness of CCL.
Failure Mechanism of LiNi0.6Co0.2Mn0.2O2 Cathodes in Aqueous/Non-Aqueous Hybrid Electrolytes
Authors: Du Leilei , Hou Xu , Berghus Debbie , Schmuch Richard , Winter Martin , Li Jie , Placke Tobias
Published: July 2022

The urgent need for higher energy density of aqueous Li-ion batteries (ALBs) cannot only be satisfied by electrolyte modifications, the utilization of layered oxide cathodes is another efficient strategy, and particularly Li[NixCoyMn1-x-y]O2 (NCM) materials are of high interest due to their high specific capacities. Concerning the H+-Li+ exchange side reaction of layered cathode in water solution, however, whether proton contamination degrades NCM-type cathodes in highly-concentrated aqueous electrolyte is an unclear but meaningful point. In this work, the underlying mechanisms responsible for degradation of NCM622 | aqueous/non-aqueous hybrid electrolyte |TiO2/LiTi2(PO4)3 (P/N=1.2:1) full-cells are explored by comprehensive studies involving in the evolution of electrochemical impendence and lattice structure changes after cycling within different operating voltage ranges. It is found that proton co-intercalation into the layered structure still takes place in high concentration aqueous/non-aqueous hybrid electrolytes, and the NCM622 cathode quickly shows degradation after being charged to higher cut-off voltage owing to severe protonation. The introduced proton can increase the diffusion barrier for Li+ ions, which in turn hinders lithiation of the de-lithiated cathode.
Utilization of an α,β-Unsaturated Carboxylic Acid to Employ an “over Cutting” Mechanism for Defect Mitigation during Cu Post-Chemical Mechanical Planarization (p-CMP) Cleaning
Authors: Dudek Abigail L. , Cahue Kiana A. , Keleher Jason J.
Published: July 2022

As features on integrated circuits (IC) continue to shrink, the implementation of chemical mechanical planarization (CMP) is a critical processing step to reduce surface topography in an effort to continue to extend Moore’s law. Specifically, Cu CMP utilizes complex slurry formulations containing an abrasive nanoparticle (SiO2) and additives (i.e., corrosion inhibitors, oxidizers, and complexing agents) to achieve angstrom level uniformity. However, one drawback to this process is the generation of detrimental surface defects that result from residual contamination (i.e., organic residues, abrasive particles, pad remnants, etc.) that are reliant on post-CMP (p-CMP) cleaning methods. Current Cu p-CMP cleaning methods implement the use of an industry standard polymer brush coupled with cleaning chemistries to remove residual contamination. It has been well established that shear and compressive forces coupled with surface active cleaning chemistries have proven to be efficient albeit with the potential for secondary defect induction (i.e., pitting, etching, scratching). Additionally, current cleaning formulations rely on additives that promote aggressive redox conditions to remove residues through an undercutting mechanism, which leads to the propagation of the aforementioned defect modes. This work focuses on the investigation of “soft” cleaning chemistries via the implementation of a structurally unique additive to create a synergy at the liquid-brush-wafer interface. More specifically, the implementation of an -unsaturated carboxylic acid (i.e., itaconic acid) has shown the capability of chemically activating an organic residue mosaic (i.e., BTA/nanoparticle) resulting in effective removal through an “overcutting” mechanism to significantly alter mechanical processing conditions. Through the implementation of corrosion studies utilizing a rotating disk electrode, the addition of itaconic acid has shown a reduction in icorr value and a shift in the passivation characteristics of the system. Open circuit potential (OCP) vs. time measurements indicates that the recovery of the passivation film is more effective in the itaconic acid formulation. A time resolved contact angle technique showed that itaconic acid had a significantly faster diffusion rate on a Cu surface coated with an exaggerated residue film indicating an enhanced surface adsorption. Furthermore, there is clear evidence that under brush conditions the presence of itaconic acid significantly enhances the removal of organic residues at the surface of a Cu substrate without the expense of effective nanoparticle removal.
Electrochemical Desalination Using a Hybrid Redox Flow Cell
Authors: Singh Siddhant , Lu Wei , Sakamoto Jeff , Kwabi David G.
Published: July 2022

Electrochemical desalination is an attractive, energy-efficient strategy for small-scale, distributed water purification systems, as compared to conventional thermal desalination or reverse osmosis. Many incumbent electrochemical desalination cells feature a combination of sodium-intercalating electrodes and polymer-based anion-exchange membranes with non-ideal permselectivities. We propose a hybrid flow cell design that features a redox-active electrolyte separated by a cation exchange membrane from a solid, anion-converting or anion-intercalating electrode. This design makes use of a dense, ceramic membrane with a greater selectivity for sodium ion conduction than polymeric ion-exchange membranes, which are also susceptible to energy losses from water crossover between dilute and concentrated salt streams. We discuss considerations that will impact the relationship among electrode and electrolyte properties, operational parameters (e.g. current density, concentration factor and water recovery percentage) and the energetic cost of desalination.
Understanding of the Furfural Electrochemical Hydrogenation and Hydrogenolysis System in a Semi-Batch Reactor
Authors: May Andrew S. , Biddinger Elizabeth J.
Published: July 2022

Furfural (FF) is a platform molecule that can undergo electrochemical hydrogenation and hydrogenolysis (ECH) over copper catalysts to form furfuryl alcohol (FA) and 2-methylfuran (FA) respectively. FA is a fine chemical used in creating furanic molds, and MF has been identified as a fuel candidate. An acidic electrolyte is necessary to obtain the MF product, however the acidic conditions are also the cause of homogeneous side reactions [1,2]. In our group we studied the kinetics of the FF ECH reactions in a 2-compartment H-cell connected to a solvent trap with inert gas sparging into the catholyte to promote the evaporation of MF to the solvent trap for capture. We showed the kinetics of the FF ECH reactions in 0.1 and 0.5M H2SO4 with concentrations of FF between 10 and 120 mM at -560mV vs RHE followed a non-competitive Langmuir-Hinshelwood model [3], in timeframes where side reactions did not influence the results significantly.

In this work, we build on our previous kinetic study by modeling the system of competing reactions and MF transfer to the solvent trap. We show the importance of sparging inert gas into the catholyte to promote evaporation of MF for collection in the solvent trap to avoid side reactions of MF in the acidic catholyte.

[1] Jung, Sungyup, and Elizabeth J. Biddinger. "Electrocatalytic hydrogenation and hydrogenolysis of furfural and the impact of homogeneous side reactions of furanic compounds in acidic electrolytes." ACS Sustainable Chemistry & Engineering 4, no. 12 (2016): 6500-6508

[2] Jung, Sungyup, and Elizabeth J. Biddinger. "Controlling competitive side reactions in the electrochemical upgrading of furfural to biofuel." Energy Technology 6, no. 7 (2018): 1370-1379

[3] May, Andrew S., Steven M. Watt, and Elizabeth J. Biddinger. "Kinetics of furfural electrochemical hydrogenation and hydrogenolysis in acidic media on copper." Reaction Chemistry & Engineering 6, no. 11 (2021): 2075-2086
Niobium Oxide Coated Mesoporous Platinum Nanoparticles for the Oxygen Reduction Reaction
Authors: Kilham Annabelle Maria , Gautam Sakshi , Gates Byron D.
Published: July 2022

Effective and economic methods of converting chemical energy into electricity or vice versa (i.e., through the use of fuel cells) must be developed to aid in the transition to renewable energy sources. One of the major barriers in the commercialization of fuel cells is the disparity in speed and efficiency between the two fuel cell reactions: the hydrogen oxidation reaction (HOR) and the oxygen reduction reaction (ORR) of which the latter is orders of magnitude slower.1 Mesoporous Pt prepared by electrodeposition has been shown to have increased activity towards the ORR than the industry standard Pt nanoparticles (NPs) supported on carbon.2 Platinum based catalysts, however, lack long term stability under acidic fuel cell conditions. One method that has been found to mitigate the long-term loss of Pt catalyst stability and activity is coating platinum with nanoscale thin films of niobium oxide.3 In this work, niobium oxide was investigated as a stabilizing coating for mesoporous Pt NP catalysts.

Mesoporous Pt NPs were synthesized via electrodeposition to form ~50 nm diameter NPs. The Pt NPs were then coated with niobium oxide films with a varying nanoscale thickness that ranged from 3 to 50 nm. The niobium oxide films were fabricated using atomic layer deposition (ALD) or electrodeposition.3,4 Scanning electron microscopy and transmission electron tomography were used to evaluate the porosity and surface morphology of the Pt NPs before and after coating with niobium oxide. X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy were used to confirm the presence and composition of the niobium oxide films. Electrochemical characterization by cyclic voltammetry and electrochemical impedance spectroscopy under acidic conditions was used to determine an optimal thickness of the niobium oxide film that stabilizes the size and morphology of the Pt NPs while maintaining catalyst activity. The Pt NPs coated with <10-nm thick niobium oxide films were observed to have an increased long-term performance in comparison to their uncoated counterparts. Stabilizing NP catalysts for improving their long-term activity is a vital step towards creating affordable alternatives to fossil fuels by maximizing renewable energy resources.

Debe, M. K. Electrocatalyst Approaches and Challenges for Automotive Fuel Cells. Nature
2012, 486, 43–51.

Paul, M. T. Y.; Gates, B. D. Mesoporous Platinum Prepared by Electrodeposition for Ultralow Loading Proton Exchange Membrane Fuel Cells. Sci. Rep.
2019, 9, 4161.

Eastcott, J.; Gates, B. D. Nanoscale Thin Films of Niobium Oxide on Platinum Surfaces: Creating a Platform for Optimizing Material Composition and Electrochemical Stability. Can. J. Chem.
2017, 96, 260–266.

Zhitomirsky, I. Electrolytic Deposition of Niobium Oxide Films. Mater.
Lett.
1998, 35, 188–193.
Mixed Metal Ni(M)/YSZ for High-Temperature CO2 Electroreduction to CO
Authors: Kamboj Vipin , Ranjan Chinmoy
Published: July 2022

Electroreduction of CO2 to fuels using renewable energy can significantly help in reducing emissions and dependence on fossil fuels. Electrochemical reduction of CO2 to hydrocarbon fuels (CHx) is energy inefficient owing to the multistep-multielectron transfer process, which possesses many kinetic limitations. The selective conversion of CO2 to CO is energy efficient. CO as product can be directly used as a fuel or converted to hydrocarbon fuels by using green hydrogen via Fischer-Tropsch reactions. We have used Ni(M)x/YSZ based electrodes to study electroreduction of CO2 on solid oxide cells at high temperature (~800∘C). Electrodes were developed on commercial standard YSZ supports using Ni(M)x/YSZ mixtures for cathode and LSM/YSZ mixtures for the anode. Electron microscopy and X-ray diffraction were used to characterize the electrode architecture and material.

The electrodes were tested using online mass spectroscopy and operando Raman spectroscopy. Ni/YSZ electrodes showed sustained performance only when H2 was added to the fuel mixture, and the reaction proceeded through a reverse water gas shift reaction (RWGS) (CO2 + H2
→ CO + H2O) in conjunction with water electrolysis with the CO originating from non-electrochemical RWGS reaction.

The reactions were also analyzed using electrochemical impedance spectroscopy. The pure Ni/YSZ cathodes showed deactivation under a pure CO2 atmosphere with the formation of NiOx species with the catastrophic breakdown at high current densities around 400 mA/cm2. The behaviour could be verified using both mass spectroscopy and operando Raman Spectroscopy. The electrochemical performance of various electrodes was compared using a 3-electrode geometry. Mixed metal oxide electrodes such as Ni(M) showed improved kinetics, with significant improvement seen in the charge transfer resistance measured.

Figure 1
Multi-Scale Modeling of Hydrogen Transport in a Porous Fuel Cell Anode
Authors: Zhang Rosa , Chowdhury Anamika , Bui Justin C , Radke Clayton J. , Weber Adam Z.
Published: July 2022

Proton-exchange-membrane fuel cells (PEMFC) are a clean energy conversion alternative to traditional fossil-fuel combustion; however, transport resistances in the electrode pose a lower-limit to catalyst loading and commercialization of PEMFCs. PEMFCs consist of simultaneous hydrogen (H2) oxidation and oxygen (O2) reduction at the anode and cathode, respectively. While oxygen transport resistances in PEMFCs have been widely studied both experimentally and analytically, hydrogen transport resistances are less understood. Herein, we present a physics-based model that encompasses multi-scale transport within the anode side of the PEMFC. The O2 in the cathode here is omitted and replaced with H2 to deconvolute O2 transport resistance contributions, similar to that of a hydrogen pump. Replication of the hydrogen pump setup allows for comparison of the model against experimental analysis of H2 gas-transport resistance in H2 limiting-current experiments, which can also inform gas transport (including oxygen) in general. Herein, we present a multi-scale analytical model of the porous anode catalyst layers and individual catalyst agglomerates that enables determination of the effects of electrode morphology such as agglomerate size, catalyst loading, etc. on H2 transport resistance through the porous electrode to complement and better understand H2 limiting current experiments and deconvolute local H2 transport resistances.

Electrodes within PEMFCs are heterogeneous porous structures formed by agglomerates of carbon particles containing Pt nanoparticles, held together by an ion-conducting polymer (ionomer). The gas transport hence involves transport through multiple phases and length-scales: (i) gas-phase transport through electrode pores at the length scale of electrode thickness (micrometer) and (ii) diffusion into the agglomerate through an ionomer film at the length scale of agglomerate radius (nanometer). Based on previous modeling efforts of varying length-scales of the catalyst layer, our analytical model adequately and simultaneously captures reaction-diffusion at all of the aforementioned scales (i.e., the electrode thickness and agglomerate radius) to better describe porous anode performance. A sensitivity analysis is subsequently performed to compare current generated against transport parameters for both scales. This work ultimately provides insight that will guide the design and engineering of future porous anodes for applications in hydrogen pumping and PEMFCs.
Ethanol Electro-Oxidation on Carbon-Supported PtRuCu/C Catalyst in a Proton Exchange Membrane Electrolysis Cell
Authors: Alqdeimat Diala Akram , Pickup Peter
Published: July 2022

The electrochemical oxidation of ethanol in cells with proton exchange membrane (PEM) electrolytes is important to develop energy technologies based on bioethanol. Direct ethanol fuel cells (DEFC) have been considered attractive power sources with high potential for use in vehicles and electronic devices, despite their low efficiencies, which need to be increased. On the other hand, ethanol electrolysis cells (EEC) can be used for hydrogen production.The importance of direct ethanol fuel cell technology for a sustainable energy future has resulted in comprehensive studies of the electrochemical oxidation of ethanol and the development of many different anode catalysts.1

Preparing catalysts with high efficiency for the ethanol oxidation reaction has been a major challenge. Although Pt has high activity for ethanol oxidation in acidic media, it is easily poisoned by adsorbed intermediates like COad and CHx, thus high overpotentials are required. PtRu alloy has become important in studies of the oxidation of ethanol, because it has high activity at low potentials. However, product analysis has shown that the main product from the oxidation of ethanol at PtRu is acetic acid and only a small CO2 yield is produced.2 Since increasing the production of CO2 is the major point to enhance the efficiency of DEFCs, it is necessary and crucial to develop and modify PtRu/C. Many researchers have introduced a third transition metal (ternary catalyst) to improve the activity and performance of PtRu/C at high potentials and also to increase the production of CO2.3,4

The purpose of this work is to explore the effect of incorporating Cu into PtRu/C catalysts on the production of CO2. A proton exchange membrane electrolysis cell was used to compare the performance of both PtRu/C and PtRuCu/C catalysts and measure the CO2 yield from the oxidation of ethanol. Interestingly, adding Cu enhanced the production of CO2, and the performance.

Acknowledgments

This work was supported by the Nature Science and Engineering Research Council of Canada and Memorial University

References

(1) Akhairi, M. A. F.; Kamarudin, S. K. Catalysts in Direct Ethanol Fuel Cell (DEFC): An Overview. Int. J. Hydrogen Energy
2016, 41, 4214–4228.

(2) Altarawneh, R. M.; Pickup, P. G. Product Distributions and Efficiencies for Ethanol Oxidation in a Proton Exchange Membrane Electrolysis Cell. J. Electrochem. Soc.
2017, 164, F861–F865.

(3) Xue, S.; Deng, W.; Yang, F.; Yang, J.; Amiinu, I. S.; He, D.; Tang, H.; Mu, S. Hexapod PtRuCu Nanocrystalline Alloy for Highly Efficient and Stable Methanol Oxidation. ACS Catal.
2018, 8, 7578–7584.

(4) Barroso, J.; Pierna, A. R.; Blanco, T. C.; Ruiz, N. Trimetallic Amorphous Catalyst with Low Amount of Platinum: Comparative Study for Ethanol, Bioethanol and CO Electrooxidation. Int. J. Hydrogen Energy
2014, 39, 3984–3990.
Ethanol and Methanol Electrolysis at Core-Shell Ru@Pt and PtRu@Pt Catalysts with Different Pt Shell-Thickness
Authors: Ali Ahmed Hashem , Pickup Peter
Published: July 2022

One of the attractive methods used to prepare hydrogen gas is the electrolysis of alcohols such as methanol and ethanol in a proton exchange membrane (PEM) cell. Platinum is the most common catalyst used to provide high selectivity for C-C bond cleavage for ethanol, leading to an increase in the amount of hydrogen gas produced. However, the cost of the Pt and poisoning of the surface by the adsorbed CO intermediate limit its use. Combining Pt with other metals such as ruthenium in the form of core-shell nanoparticles enhances its ability for alcohol oxidation [1,2]. Therefore, more hydrogen gas is evolved in a PEM electrolysis cell, especially at lower applied potentials. In addition, these modified catalysts can be used in the anodes of direct alcohol fuel cells.

Here, we aimed to prepare Pt-based core-shell nanoparticles in which commercial catalysts PtRu and Ru were used as the core, and different amounts of Pt were deposited on their surface as a shell (PtRu@Pt and Ru@Pt). These catalysts were prepared using the polyol method without adding any stabilizer that would block their surface and affected their alcohol oxidation activity. The formation of these core-shell nanoparticle catalysts was confirmed by using thermogravimetric analysis, transmission electron microscopy, scanning electron microscopy with an energy dispersive X-ray analyzer, X-ray diffraction and X-ray photoelectron spectroscopy. Moreover, the effect of the Pt thickness on methanol and ethanol electrochemical oxidation was studied using cyclic voltammetry at room temperature and a PEM electrolysis cell at 80 °C.

Results show that methanol and ethanol oxidation activity increased greatly as the thickness of the Pt shell was increased, although the half potential was shifted to a higher potential. Moreover, the addition of the Pt to the shell increased the limiting current, indicating that the selectivity toward CO2 formation increased and that more hydrogen was being produced. Finally, Ru as a core showed a lower improvement for methanol oxidation than PtRu. However, Ru@Pt catalysts with more than one Pt monolayers gave higher ethanol oxidation performances than the PtRu@Pt catalysts.

Acknowledgments

This work was supported by the Natural Science and Engineering Research Council of Canada and Memorial University.

References:

T. M. Brueckner, E. Wheeler, B. Chen, E. N. El Sawy and P. G. Pickup, J. Electrochem. Soc., 166, F942 (2019).

E. El Sawy, T. M. Brueckner and P. G. Pickup, J. Electrochem. Soc., 167, 106507 (2020).
(Invited) U.S. Department of Energy Initiatives in Lithium Battery Recycling and the Supply Chain
Authors: Gillard Samm
Published: July 2022

For the U.S. to meet climate change and circular economy goals, to ensure good stewardship of critical materials, and to meet strategic supply chain goals for economic development and national security, a strong commercial recycling industry for recycling is vital. Identified by the blueprint developed by the Federal Consortium for Advanced Batteries (FCAB) and the Administration’s 100 Day report for high-capacity batteries as a key strategic focus area, recycling offers the strongest pathway to ensuring the U.S. can capitalize on the strong market demand for EVs and to ensure the materials are available for the U.S. to reintegrate into the supply chain. However, recycling alone is not enough to enable the U.S. goals to create a resilient and sustainable supply chain. Recycling needs to consider all end-of-life potential and challenges for lithium ion batteries, and the requalification of those materials in the battery supply chain. This requires a look at all supply chain segments as a whole to determine the areas for largest impact for sustainability and economic development.
Acidic Chloride Leaching of NMC Cathodes Combined with Solvent Extraction for the Production of Value Metals from Spent Lithium-Ion Battery
Authors: Chagnes Alexandre , Xuan Wen
Published: July 2022

Lithium-ion battery is the technology of choice in the development of electric vehicles. This technology is now mature although there are still many challenges to increase their energy density while ensuring an irreproachable safety of use. For this goal, it is necessary to develop new cathodic materials that can be cycled at higher voltages and electrolytes compatible with these materials. But the challenge does not only concern the production of efficient batteries for the electrochemical storage of energy since lithium-ion battery technology relies on the use of critical and/or strategic value resources. It is therefore crucial to include Lithium-ion batteries development in a circular economy approach very early. In particular, optimized recycling and reuse of battery components must both minimize their impact on the environment and limit geopolitical issues related to tensions on the mineral resources necessary for lithium-ion battery production. Although recycling will never replace mining, it reduces resource dependence by ensuring the presence of exploitable resources in the territory, which is particularly important for countries like France where exploited or exploitable resources are limited.

This conference addresses the development of a new hydrometallurgical process combining leaching of cathodic material from spent lithium-ion battery in acidic chloride media and solvent extraction process. Most of recycling processes reported in the literature rely on the sulphate route and a few studies investigate the potentialities of the chloride route despite many advantages and the possibility to develop new chemistry, which could get easier the metal separation. The leaching mechanisms and the solvent extraction equilibria will be presented in this conference. Based on the comprehension of the physicochemistry of leaching and solvent extraction, the present study will introduce a new hydrometallurgical process for the production of cobalt, nickel, manganese and lithium from spent cathodic materials.