bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Durable Large-Sized CO2 Electrolysis Cells for Industrial Applications
Authors: Fujiwara Naoya , Kofuji Yusuke , Mikoshiba Satoshi , Kitagawa Ryota , Matsunaga Atsushi , Kikuchi Isamu , Shimotori Soichiro 
Published: February 2024

Utilization of carbon dioxide (CO2) as a feedstock of valuable chemicals is necessary to achieve carbon neutrality. Toshiba is developing the low-temperature zero-gap type CO2 electrolysis cells to produce carbon monoxide (CO) [1,2]. CO can further be converted into various chemicals and fuels by catalytic reactions with hydrogen. To make the CO2 electrolysis technology industrially feasible, it is necessary to establish high-throughput system by expanding the electrode area and stacking the cells. Large-sized cells and stacks often suffer from low Faradaic efficiency for the CO production, which is related to insufficient and nonuniform supply of reactant CO2 gas to the cathode reaction sites. This time we focused on the development of large-sized single cells and fabricated an electrolysis cell with 400 cm2 electrodes. With properly designed gas flow plates and gaskets, the cell voltage and the CO Faradaic efficiency of the fabricated cell at a current density of 400 mA cm-2 were comparable to those of the previously developed smaller cells with 4 cm2 electrodes. The CO concentration in the cathode outlet gas reached ca. 80% by controlling the inlet CO2 flow rate. Stability is another essential property of CO2 electrolysis cells required for the industrial application. Cathode flooding and salt precipitation are major stability issues characteristic of relatively short-term operations, whose detailed mechanism is still in debate [3]. To mitigate those stability issues, we focused on the cathode inlet humidity and the pressure difference between the cathode and the anode. The former is related to the salt concentration in electrolyte solution around the cathode reaction sites, and the latter is related to the convection of electrolyte from the anode side to the cathode side. By controlling those parameters, stable performance over 100 h was achieved.
Part of this work was commissioned by Ministry of the Environment, Government of Japan.
[1] Y. Kofuji, A. Ono, Y. Sugano, A. Motoshige, Y. Kudo, M. Yamagiwa, J. Tamura, S. Mikoshiba, and R. Kitagawa, Chem. Lett., 50, 482-484 (2021).
[2] Y. Kiyota, Y. Kofuji, A. Ono, S. Mikoshiba, and R. Kitagawa, 242nd ECS Meeting, I05-1942 (2022).
[3] M. Sassenburg, M. Kelly, S. Subramanian, W. A. Smith, and T. Burdyny, ACS Energy Lett., 8, 321-331 (2023).
(Invited) Long Term Operation of Photoelectrochemical Devices: Experiments and Modeling
Authors: Haussener Sophia 
Published: February 2024

Achieving long term operation while maintaining a high energy conversion efficiency and large production rates is one of the main challenges for enhancing the economic competitiveness of solar fuel producing photoelectrochemical devices [1]. I will discuss computational and experimental methods to characterize the degradation of photoelectrochemical devices. The models consider multi-scale approaches and multi-physics phenomena [2]. This is required in order to properly account for all the competing and convoluting effects and to properly extract and quantify the degradation from experimental data. I will present our experimental setup that consists of a multi-PEC cell array in order to obtain sufficient and statistically representative data. Additional experiments under high-flux solar irradiation conditions are presented that allow – in conjunction with the model – for the extraction of degradation characteristics and the development of accelerated age testing procedures. I will also report on the long term operation of our outdoor photo-electrochemical system demonstration operating under concentrated light [3].
[1] M. Dumortier, S. Tembhurne, S. Haussener, Energy Environmental Science, 8: 3614-3628, 2015.
[2] F. Nandjou, S. Haussener, ACS Applied Materials & Interfaces. 10.1021/acsami.2c08204, 2022.
[3] I. Holmes-Gentle, S. Tembhurne, C. Suter, S. Haussener, Nature Energy, 10.1038/s41560-023-01247-2, 2023.
The Localized Surface Plasmon Resonances (LSPR) Origin of W18O49 and Application in Photocatalysis
Authors: Zhaoyu Ma , Zhang Junying 
Published: February 2024

A key solution for high-efficiency solar-to-fuel conversion is to fabricate semiconductor photocatalysts with ultra-broad spectral absorption and high charge-carriers utilization efficiency [1]. The localized surface plasmon resonances (LSPR) effect of W18O49 induces visible and near-infrared (NIR) light absorption efficiently, realizing full-spectrum solar-light driven photocatalysis [2]. Therefore, it is meaningful to study the LSPR origin and seek ways to make full use of photo-induced hot electron of W18O49. In our work, by density-functional theory calculation, the LSPR has been proposed to originate from the localized electron confinement around lattice W5+–W5+ pairs in the unique structure of W18O49, which explains the experimental results that W18O49 has a broad absorption ranging from visible to NIR region, independent of the particle shape and size. Hierarchical-structured W18O49 microflowers with high absorbance have been coated with ZnIn2S4 nanosheets to achieve cocatalyst-free photocatalytic composite, which exhibits outstanding H2 production of 902.57 µmol within 3 h under simulated solar-light. [3] Z-scheme photocatalytic heterojunction of W18O49 microflowers and g-C3N4 nanosheets has been constructed through electrostatic self-assembly method, which shows higher photocatalytic hydrogen production performance than the counterpart synthesized by hydrothermal method. [4]

Reference

[1] Q. Wang, K. Domen, Chem. Rev. 2020, 120, 919−985.
[2] Z. Y. Zhang, J. D. Huang, Y. R. Fang, et al., Adv. Mater. 2017, 29, 1606688.
[3] Y. Lu, X.F. Jia, Z.Y. Ma, et al., Adv. Funct. Mater., 2022, 32, 2203638.
[4] Z. Y. Ma, W. P. Li, X. F. Jia, et al., Mater. Today. Adv. 2022, 15, 100249.
(Invited) Plasmonic Aerogels for Gas-Phase Photocatalytic Reactions
Authors: Zhi Mingjia 
Published: February 2024

As a special form of material, aerogel has emerged as a promising type of photocatalyst. Owing to the large specific surface area and the developed pore texture, it would be suitable to drive various gas-phase reactions such as CO2 reduction and CH4 conversion. More importantly, the size of the fundamental building blocks in an aerogel, which is typically 5-20 nm, is approaching that of the noble metals with the surface plasmon resonance (SPR) effect. Innovated by Rolison and Niederberger(1, 2), aerogels with plasmonic effect have been extensively studied as photocatalysts for hydrogen evolution and dye degradation in liquid medium
This talk then aims to introduce some of our recent results on the construction and evaluation of plasmonic noble metal/ceria composite aerogels, which cover the content from the synthesis to new applications. Modified synthesis methods are developed for the rational incorporation of plasmonic metal nanoparticles such as Ag and Au into an aerogel backbone in one step, which offers an alternative route to tune the composition and size of these nanoparticles, or even building single-atom composite aerogels in the conventional sol-gel methodology(3). When these plasmonic aerogel photocatalysts are applied for gas-phase CO2 reduction and non-oxidative CH4 coupling reaction, good performance is observed. The synergistic effect of plasmonic sensitizer and co-catalyst is discussed and is responsible for the performance enhancement.

P. A. DeSario, J. J. Pietron, A. Dunkelberger, T. H. Brintlinger, O. Baturina, R. M. Stroud, J. C. Owrutsky and D. R. Rolison, Langmuir, 33, 9444 (2017).

F. Rechberger and M. Niederberger, Nanoscale Horizons, 2, 6 (2017).

M. Wu, C. Ouyang, Z. Ye, S. Li, Z. Hong and M. Zhi, ACS Applied Energy Materials, 5, 7335 (2022).
Layered Nanocomposites of Polymer-Functionalized Reduced Graphene Oxide and Borocarbonitride with MoS2 and MoSe2 and Their Hydrogen Evolution Reaction Activity
Authors: Servottam Swaraj , Rao Chintamani Nagesa Ramachandra 
Published: February 2024

Two dimensional heterostructure have been widely investigated for various applications in electrochemistry such as water splitting and battery storage. These heterostructures are mainly formed due to vander waals interaction, covalent cross-linking and electrostatic interactions. Herein, we have prepared nanocomposite of positively charged poly (diallyldimethylammonium chloride) (PDDA, shown as P)-functionalized reduced graphene oxide (RGO) and borocarbonitride (BC6N, shown as BCN for simplicity) sheets with layers of negatively charged MoS2 and MoSe2 by electrostatic interaction in solution phase. The nanocomposites exhibit superior photocatalytic hydrogen evolution reaction (HER) activity compared to the individual components, and the value increases with the MoS2/MoSe2 content. The highest photocatalytic HER activity obtained is 11230 μmol h–1 g–1 in the nanocomposite P.RGO-MoS2, with a P.RGO-MoS2 ratio of 1:5. The P.RGO-MoSe2 (1:5) and P.BCN-MoS2 (1:5) nanocomposites exhibit somewhat lower activities of 9540 and 8593 μmol h–1 g–1, respectively. Prompted by literature reports that carbon-rich BCNs are efficient HER electrocatalysts, we have examined the electrocatalytic HER activity of P.BCN-MoS2 (1:1, 1:5, and 1:7) nanocomposites. The electrocatalytic HER activity of P.BCN-MoS2 (1:5) is found to be extraordinary, with an onset potential of −50 mV (vs RHE), comparable to that of platinum.
References: -

Geim, A. K. & Grigorieva, I. V. Van der Waals heterostructures. Nature 2013 499:7459
499, 419–425 (2013).

Pramoda, K., Gupta, U., Ahmad, I., Kumar, R. & Rao, C. N. R. Assemblies of covalently cross-linked nanosheets of MoS2 and of MoS2–RGO: synthesis and novel properties. J Mater Chem A Mater
4, 8989–8994 (2016).

Pramoda, K., Servottam, S., Kaur, M. & Rao, C. N. R. Layered Nanocomposites of Polymer-Functionalized Reduced Graphene Oxide and Borocarbonitride with MoS2 and MoSe2 and Their Hydrogen Evolution Reaction Activity. ACS Appl Nano Mater
3, 1792–1799 (2020).

Figure 1
(Invited) Dye-Sensitized Molecular Photoelectrodes for CO2 Reduction Using Water as a Reductant
Authors: Ishitani Osamu 
Published: February 2024

Photocatalytic CO2 reduction using visible light and water as a reductant has been one of the important targets for solving global warming problem and shortage of energy and carbon resources. In this presentation, I talk about two projects, i.e., (1) supramolecular photocatalysts with both functions as photosensitizer and catalysts and (2) photocatalytic CO2 reduction coupled to water oxidation.
(1) Highly efficient supramolecular photocatalysts for CO2 reduction1-3

Since CO2 is the most oxidized state of carbon, one-electron reduction of CO2 is an extraordinarily high endergonic reaction. From the viewpoints of low-energy light application, the multi-electron reduction of CO2 via chemical reactions promises to be a more valuable process. This is a main reason why both a photosensitizer and a catalyst are required to promote efficient photocatalytic CO2 reduction. We have developed so-called supramolecular photocatalyts that have both the photosensitizer and the catalyst units. This bonding in the supramolecular photocatalysts can accelerate electron transfer between the two units, which improves the performance of the photocatalytic system, especially on the surface of photofunctional solid materials as described below.
(2) Molecular photoelectrodes for photocatalytic CO2 reduction with water as a reductant 1,4

The molecular photocatalytic systems have a weakness, i.e., weak oxidation power in the excited state. For practical application, water should be used as an electron donor. For overcoming this problem, we have developed a hybrid system consisting of the supramolecular photocatalyst and semiconductor electrodes. The hybrid photoelectrochemical cell consisting of this hybrid photocathode and n-type semiconductor photoanode induced visible-light-driven CO2 reduction with water as a reductant to generate CO and O2.

References

“Photocatalytic Systems for CO2 Reduction: Metal-Complex Photocatalysts and Their Hybrids with Photofunctional Solid Materials” Kumagai, H.; Tamaki, Y.; Ishitani, O., Acc. Chem. Res.
2022,
55, 978-990.

“Mechanistic study of photocatalytic CO2 reduction using a Ru(II)-Re(I) supramolecular photocatalyst” Kamogawa, K.; Shimoda, Y.; Miyata, K.; Onda, K.; Yamazaki, Y.; Tamaki, Y.; Ishitani, O., Chem. Sci.
2021,
12, 9682-9693.

“Supramolecular Photocatalysts for the Reduction of CO2” Tamaki, Y.; Ishitani, O., ACS Cat.
2017,
7, 3394-3409.

“Supramolecular photocatalysts fixed on the inside of the polypyrrole layer in dye sensitized molecular photocathodes: application to photocatalytic CO2 reduction coupled with water oxidation. Kuttassery, F.; Kumagai, H.; Kamata, R.; Ebato, Y.; Higashi, M.; Suzuki, H.; Abe, R.; Ishitani, O., Chem. Sci.
2021,
12, 13216-13232.

Figure 1
(Invited) Electrocatalytic Reduction of Carbon Dioxide over Aluminum-Added Coppor Oxide Gas Diffusion Electrode
Authors: Minegishi Tsutomu , Komori Daiki , Ebe Hiroji , Kumagai Hiromu , Sugiyama Masakazu 
Published: February 2024

Electrochemical cells are the key technologies for construction of carbon neutral society to produce hydrogen from water and produce useful chemicals from carbon dioxide utilizing renewable energy. Copper species are the unique catalysts for electrochemical carbon dioxide reduction reaction (CO2RR) with capable of producing C2+ products such as ethanol and ethylene. Selective production of target chemical is one of the most important requirements for the catalysts, and addition of different elements and surface modifications have been reported to be beneficial for the selective production.
In the present study, copper oxides-based catalysts prepared with electroless plating techniques were examined for electrochemical CO2RR. To conduct CO2RR at relatively high current densities, the catalysts were examined in the form of gas diffusion electrode (GDE). The Cu2O based GDE was prepared by the combination of physical vapor deposition and electroless plating on hydrophobized carbon paper coated with mesoporous carbon layer. After the electroless plating treatment, the metal precursors were successfully converted to core-shell structured electrocatalyst with Cu2O shell and Cu core. By introducing different elements such as aluminum to the precursor, metallic Cu, the different element added catalysts were successfully prepared in the shape of GDE. Addition of different element significantly improved durability of the core-shell structured catalysts and, as a result, faradaic efficiency of ethylene of 24 hours after starting electrolysis was increase from 32% to 47% under applying cathodic current of 260 mAcm-2. Further surface modifications with Nafion enhanced the durability and the faradaic efficiency of ethylene maintained >50% for over 48 hours and reached about 60% in maximum.
In the presentation, we will discuss about the detailed structure of the electrocatalysts, results of full-cell test, and longer durability test over 100 hours.
(Invited) Limitation of Molecular Twisting: Upgrading a Donor-Acceptor Dye to Drive H2 Evolution
Authors: Mul Guido , Zhu Kaijian , Huijser Annemarie 
Published: February 2024

Dye-sensitized photoelectrochemical cells (DSPECs) have attracted wide attention to convert solar energy into high-energy chemicals. A DSPEC consists of a photoanode performing the oxidation half reaction and a
photocathode performing the reduction half reaction. In this presentation I will demonstrate how the performance of a dye-sensitized photocathode can be manipulated to enhance performance and even produce hydrogen! We have used a state- of-the-art dye (D-A P1 dye) on the surface of optimized NiO, and co-adsorbed myristic acid (Tetradecanoic Acid), which has a carboxyl anchoring group and a long apolar alkyl chain. Time-resolved photoluminescence and Density Functional Theory studies show that twisting lowers the energy levels of the photoexcited D-A dye, while twisting is inhibited in case myristic acid is co-adsorbed on the NiO surface. The presence of myristic acid also favors light-induced charge separation, as apparent from femtosecond transient absorption, and increases the apparent photocurrent. Very interestingly, only in the presence of myristic acid, light-induced H2 evolution is observed in aqueous media, despite the absence of a H2 evolution catalyst. We assign the H2 generation to a synergetic effect of inhibited twisting of the D-A dye radical anion increasing its electrochemical potential, combined with charge transfer and conversion of H+ on the hydroxylated NiO surface. Our work illustrates the importance of understanding effects of photoinduced intramolecular twisting and demonstrates that control thereof offers a simple design approach for efficient solar fuel devices.
Mass Transport in a Gas-Fed CO2 Electrolyzer with a Forward-Bias Bipolar Membrane
Authors: Dessiex Matthieu , Fischer Robert , Haussener Sophia , Buechi Felix N. 
Published: February 2024

In the context of synthetic fuel and chemical production, CO2 electrolyzers using bipolar membranes (BPM) in forward bias have proven to overcome current limitations in state-of-the-art alkaline CO2 electrolyzers. These limitations are CO2 cross-over and carbonate deposition in the cathode catalyst layer, which limit the large-scale development of alkaline CO2 electrolyzers. Devices with a BPM in forward bias (Figure 1) solve these issues by setting the anode under acidic conditions while keeping the cathode alkaline. This configuration prevents carbonate ions to reach the anode and thus suppresses CO2 cross-over. Moreover, it allows pure water as an anolyte. Pure water eradicates unwanted cation cross-over and thus prevents carbonate deposition at the cathode. However, the use of a BPM for CO2 also has limitations. The most prominent ones are low stability and high over-voltage. These are partly caused by the complex and unexplored water transport.
This work presents efforts to characterize and optimize different water transport phenomena. For this, we study cells of different complexity. It implies understanding first the water diffusion across the membrane, by setting a water concentration gradient between the electrodes and analyzing water transport by dew point measurement. The membrane hydration state can be determined with the simultaneously measured ion conductivity. Then, the water transport of a full cell is measured in parallel to its electrochemical performance. In this setup, a gas chromatograph and a mass spectrometer measure the selectivity of the cathode reaction.
The optimal conditions at the cathode are a subtle balance between excess and scarcity of water. Water is a reactant in the CO2 reduction reaction and helps to humidify the membrane, ensuring good ionic conductivity. Additionally, water is formed by ion recombination at the BPM junction affecting the membrane hydration state. Still, we observe that the water supply at the cathode can be insufficient, especially at high current density. However, too much water can flood the cathode and block CO2 transport to the catalyst layer.
In summary, we deliver a clearer picture of the water paths and demonstrate that optimized material and operating conditions help to overcome current limitations.

Figure 1
Early Failure Detection for CO2 Reduction Electrolyzers Via in-Line Electrochemical Impedance Spectroscopy
Authors: O'Brien Colin P. , Warkentin Hugh , Holowka Sarah , Maxwell Benjamin , Awara Mariam , Bouman Mark , Shayesteh Ali , Nicholas Rachael , Ip Alexander , Elsahwi Essam , Gabardo Christine , Sinton David 
Published: February 2024

The electrochemical CO2 reduction reaction (CO2RR) presents the opportunity to produce chemical feedstocks and fuels directly from CO2. Recent achievements in energy efficiency and current density are approaching the targets required for commercial viability; however, stability remains more than two orders of magnitude below the required 80,000 h. In CO2RR there is a challenge to distinguish the cause of failure among many possibilities. Failure can result from initial setup (e.g. over or under compression of the membrane and electrodes), gradual degradation of components (e.g. cathode and anode catalyst restructuring and dissolution), accumulation of products or byproducts (e.g. alcohols or salt accumulation), or immediate failures (e.g. a hole in the membrane or a short circuit). These failure modes must be addressed to reach the targeted stability needed for the wide-scale adoption of this technology. Early identification and mitigation of these failures would increase the electrolyzer lifetime and the commercial viability of CO2RR electrolyzers.
Current techniques to characterize failures of the electrolyzer rely on post-mortem analysis of cell components. The analysis of individual components after operation may not accurately reflect their state in operando. There are techniques that are capable of analyzing the cell in operation (e.g. XAS, Raman, and TEM), but these typically require modified cell architectures and are operated at lower reaction rates. To effectively diagnose failure, the analysis technique should be applied to electrolyzers operating under realistic conditions.
Here we implement an in-line real-time electrochemical impedance spectroscopy (EIS) technique to monitor CO2RR electrolyzers during operation. EIS is a non-destructive technique that can provide continuous information on the performance of specific components within the electrolyzer. We characterize common failure modes, such as poor compression, salt formation, catalyst degradation, and short circuits, and their identifying changes to the EIS response. We extract key electrochemical parameters from the EIS response and use them to develop a framework to identify and prevent the most common failure modes. Among other applications, this framework allowed for the detection of anode catalyst degradation 11 h before other indicators, such as cell voltage or product selectivity. This technique and framework can be applied to monitor CO2 electrolyzers as they are scaled and stacked.