bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Design Consideration of an IGFC System with CO2 Capture
Authors: Liu Zhien , Li Pingping , Liu Changlei , Wang Hanlin , Li Chufu 
Published: February 2020

Due to vast coal reserve and its lower cost, integrated Gasification Combined Cycle (IGCC) and Integrated Gasification Fuel Cell (IGFC) power generation system are being developed to use coal effectively and reduce air pollution. Compared to IGCC, the advantage of IGFC is higher efficiency and lower overall cost, especially pressurized system. An IGFC system is being developed using syngas as fuel with CO2 capture at National Institute of Clean Low-Carbon Energy (NICE). In the system, the high temperature solid oxide fuel cell (SOFC) stacks are used to convert fuel to electricity. The system design principles, syngas composition and SOFC stack performance effect on system efficiency, and the system cost will be discussed, estimated, and analyzed based on the model established. The method of CO2 capture will also be discussed and recommended based on experimental data.
There is variety of impurities in syngas, such as sulfur, PH3, Siloxane, chlorine, Arsine, etc, which may poison SOFC anode and significantly affect system performance. Syngas cleaning is needed before powering the stack using syngas. Besides, there is significant amount of CO2 in initial syngas which will dilute flammable H2 concentration which may affect both power generation and the efficiency of the system, which eventually resulted in higher cost. Two syngas cleaning methods were evaluated and recommendation was made based on experimental results.
Syngas composition may vary based on the cleaning method to be used. The CO in syngas has two potential negative effects on SOFC operation. First, the Boudouard reaction is of concern in the temperature range from 500 to 600oC when CO can dissociate into C and CO2 (equation 1), which is called carbon coking. The method to prevent carbon coking was discussed. Second, if dry syngas is used as fuel, the water-gas shift reaction (equation 2) may occur in SOFC stack with the accumulation of water steam formation from electrochemical reaction, which is exothermic. The heat release from water-gas shift reaction would increase temperature difference between stack inlet and outlet which make it difficult to manage stack temperature to achieve optimized performance. SOFC stack electrical efficiency was analyzed with different fuel compositions and under different designed operation conditions, such as anode recycle ratio, using the model established.
CO ↔ CO2 + C (1)
CO + H2O ↔ H2 + CO2 (2)
In order to capture CO2 from exhaust fuel gas, CO2 has to be concentrated higher than 98% first in the tail gas. Technical approaches were identified. Small scale matrix tests show promising results to meet expectation. Fabrication of scale-up testing equipment for technology verification is in process.
Fabrication and Characterization of Thin Film SrCo0.8Nb0.1Ta0.1O3-Δ By Pulsed Laser Deposition
Authors: Ryu Sangbong , Yu Wonjong , Lee Sanghoon , Jeong Wonyeop , P Arunkumar , Cho Gu Young , Cha Suk Won 
Published: February 2020

High working temperature(≥800 °C) of solid oxide fuel cell(SOFC) causes high cost of balance of plant, long start up time, and low durability. To overcome these barriers, lowering the working temperature of SOFC is one of the most attractive ways and such strategy has been researched through the fabrication of thin electrolyte and developing new perovskite cathode material. Recently, mixed ionic electronic conducting(MIEC) cathode material, SrCo0.8Nb0.1Ta0.1O3-δ (SCNT), has been developed by Li et al. and the SOFC with the cathode showed high performance(1.22W/cm2) at low working temperature (500 °C) with 14µm thick gadolinia doped ceria(GDC) electrolyte[1]. To apply SCNT to SOFC with thin electrolyte(≤1µm), the cathode must be fabricated on the electrolyte without high temperature sintering process(≥1000 °C) because of the weak mechanical strength of thin electrolyte. In this work, pulsed laser deposition(PLD) method was employed for the fabrication of thin film SCNT. PLD has been used widely for perovskite material deposition because of its high preservability of stoichiometric ratio of its original target material. However, the deposition temperature of PLD has a great influence on both physical and chemical structure of the film which means oxygen reaction activity(ORR) of the film also varies as temperature changes. Therefore, thin film SCNT was deposited by PLD at various temperature condition in this work to see the diversity of thin film characteristic for understanding the feasibility of application of SCNT to thin film SOFC (TF-SOFC).
Powder and PLD target of SCNT were both prepared by the method Li et al. used, solid state reactive sintering(SSRS). The film was firstly deposited on Si wafer at various temperature (room temp, 500, 600, 700 °C) by PLD. Field emission scanning electron microscope (FE-SEM) and focused ion beam-SEM (FIB-SEM) were used to see the nano-structure of the film and deposition rate. 75mTorr of oxygen atmosphere was enough to make the structure of thin film deposited at room temperature very porous but dense film was observed at the temperature higher than 500 °C. The atomic ratio and crystallinity of each film were identified by X-ray spectroscopy(XPS) and X-ray diffraction(XRD) respectively. Through the understanding the physical and chemical variation of PLD deposited SCNT at different temperature condition, the best PLD deposition condition of SCNT for TF-SOFC was derived.

Acknowledgment

This work was supported by the Global Frontier R&D Program on Center for Multiscale Energy System funded by the National Research Foundation under the Ministry of Science, ICT & Future Planning, Korea (2012M3A6A7054855)

References

[1] M. Li et al., “A niobium and tantalum co-doped perovskite cathode for solid oxide fuel cells operating below 500 °c,” Nat. Commun., vol. 8, no. 5, pp. 1–9, 2017.
Electrochemical Ammonia Synthesis Using a BZCYYb4411 Proton Conductor
Authors: Hortance Nicholas Michael , Hatzell Kelsey B. 
Published: February 2020

The Haber Bosch process is the dominant route to synthesizing ammonia. Ammonia is an important component in fertilizers, which are widely used across the agriculture community. Dependence on the Haber Bosch process is detrimental because: (1) this process operates at high temperatures (~450°C)1 and pressures (150-300 bar) and accounts for 2% of the worlds energy supply2, (2) contributes 1% of all CO2 emissions, and (3) is typically centralized which limits access in developing worlds. Electrochemical ammonia production has the potential to greatly reduce society’s carbon footprint and energy consumption, as well as increase ammonia production in developing worlds and rural communities. This type of ammonia synthesis method has been shown to operate with air and water sources as opposed to highly pure nitrogen and hydrogen reactants used in commercial plants. Solid state electrochemical systems are able to operate at elevated temperatures (300-600 °C) unlike ambient processes (low temperature fuel cells) and thus have the potential for higher yields. Solid state ceramic proton conductors show high ionic conductivities (1E-2 Scm-1 at 600°C)3 and are stable in this intermediate temperature range. Currently, the investigation of intermediate temperature ion conductors in solid state ammonia synthesis is nascent but growing in interest. Herein, we describe the synthesis and processing of a highly conductive proton conductor BaZr0.4Ce0.4Y0.1Yb0.1O3-
δ (BZCYYb4411) (Fig. 1a,b) is characterized and implemented in a solid state fuel cell arrangement. BZCYYb4411 is synthesized using a solid-state reaction route and Ag-Pd catalyst is used to make a symmetric cell. In this one chamber reactor employing 3% H2/N2, the faradaic efficiency and ammonia production rate is explored at different temperatures and operating voltages to elucidate the optimal conditions for ammonia synthesis.
(1) Kyriakou, V.; Skodra, A.; Stoukides, M.; Vasileiou, E.; Garagounis, I. Electrochemical Synthesis of Ammonia in Solid Electrolyte Cells. Front. Energy Res.
2014, 2 (January), 1–10.
(2) Martín, A. J.; Shinagawa, T.; Pérez-Ramírez, J. Electrocatalytic Reduction of Nitrogen: From Haber-Bosch to Ammonia Artificial Leaf. Chem
2019, 5 (2), 263–283.
(3) Choi, S.; Kucharczyk, C. J.; Liang, Y.; Zhang, X.; Takeuchi, I.; Ji, H. Il; Haile, S. M. Exceptional Power Density and Stability at Intermediate Temperatures in Protonic Ceramic Fuel Cells. Nat. Energy
2018, 3 (3), 202–210.

Figure 1
Mo Thio Molecular Complexes As Water-Soluble Catalysts for the Photocatalytic Hydrogen Evolution Reaction on 2D Materials
Authors: Barbosa Juliana Barros , Taberna Pierre-Louis , Chane Ching Jean-Yves , Gerber Iann , Poteau Romuald , Balocchi Andrea , Marie Xavier 
Published: February 2020

Producing hydrogen fuel through solar-driven photoelectrochemical (PEC) water splitting represents an attractive approach for the development of sustainable energy. 2D semiconducting Transition Metal dichalcogenide (TMDC) nanosheets are attractive materials for solar energy conversion and have been applied as photocathodes for the Hydrogen Evolution Reaction (HER). To improve the performances of the photocathodes, optimized TMDC film microstructure was proposed involving a self-assembly at a liquid-liquid interface. In addition, in combination with a hexyl-tri-silane surfactant treatment, molecularly thin 2D WSe2 nanosheets films were coated by a Pt-Cu catalyst. In this process, the increase of photocurrent resulting from the surfactant treatment was attributed to edge site passivation of the 2D nanosheets drastically decreasing the charge carrier recombination site density. Indeed, for a large scale development of these photocathodes, replacement of Pt-Cu by a precious metal-free catalyst is highly desirable. In this talk, we will present our recent results concerning Mo thio complexes as catalysts anchored on WSe2 nanosheets for efficient water splitting under visible light irradiation. We used WSe2 films prepared by a simple film forming process, i.e. drop casting, and an aqueous environmentally friendly process for the catalyst preparation.
Active molecular Mo catalysts including (Mo2S12)2- were deposited via a selection process from a solution allowing the deposition of the most interactive Mo complexes towards the WSe2 nanosheets thus improving their anchorage and durability. Our ultrathin films showed a current density up to -2 mA/cm² at 0 V vs NHE without any passivation additive such as HTS surfactant. The respective contributions namely in electro-catalysis and site passivation observed experimentally for the various molecular Mo complexes involved were supported by DFT calculations of i) Adsorption energies of the Mo thio complexes on the WSe2 substrates and ii) Free energies changes for the hydrogen Evolution Reaction on the various adsorbed molecular Mo complexes. These results will greatly help to better design molecular photo-catalysts for photo-electrodes displaying high surface recombination site density.
Shedding Light on the Stability of Photoelectrochemical Water Splitting Cells
Authors: Nandjou Fredy , Haussener Sophia 
Published: February 2020

The instability of the semiconductor-electrolyte interface is a major challenge for the development and implementation of long-lasting photoelectrochemical (PEC) solar fuel producing devices [1]. Kinetic studies, incorporating the competing photocorrosion and fuel producing reaction mechanisms at the photoelectrode of the PEC device, predicted that some thermodynamically unstable semiconductors could be kinetically stable as a result of their extremely low photocorrosion current and therefore enable acceptable lifetimes [2].
We developed a 1-D multi-physics model that coupled the reactions kinetics to photo-physical processes occurring in the PEC device. These processes include radiation absorption, charge carrier generation, charge transport, charge transfer from the semiconductor to the electrocatalyst, charge transport in the catalyst and photocorroded layers, and mass transport in the electrolyte phase. The model accounted for the impact of surface chemical properties, catalyst activity, charge carrier density in the semiconductor and in the electrocatalyst, and electrolyte acidity. In parallel, a bonding model was developed to predict the surface back-bond potential of the semiconductor, which is known in highly impact on the stability [2].
When applied to some promising semiconductors for photoelectrochemical water splitting, the model provided trends on the dependence of the stability of the semiconductor-electrolyte interface on irradiation intensity, semiconductor and electrocatalyst properties, and mass transport in the electrolyte.
[1] Fredy Nandjou and Sophia Haussener, Degradation in photoelectrochemical devices: review with an illustrative case study, Journal of Physics D: Applied Physics 50, 2017.
[2] Fredy Nandjou and Sophia Haussener, Kinetic Competition between Water‐Splitting and Photocorrosion Reactions in Photoelectrochemical Devices, ChemSusChem 12, 2019.
(Invited) Bi-Functional Electrocatalysts for Water Splitting and Metal-Ion Batteries
Authors: Fan Hong Jin 
Published: February 2020

Water electrolysis, fuel cells, and metal-air batteries all require efficient and cheap electrocatalysts that can significantly lower the reaction overpotentials. Bimetallic alloys and their oxides or nitrides compounds are particularly interesting as non-precious metal electrocatalyst materials for HER and OER, because of their tailorable electronic structure, conductivity, and surface chemistry. Our group has been actively working on nanoarray materials directly grown on conductive substrates as electrodes for supercapacitor, batteries and electrocatalyst.
In this talk, I will present two main results about surface and interface engineering/functionalization of array-type electrocatalysts for water splitting and for meal-ion batteries.
(1) RF nitrogen and carbon plasma as a highly effective technique for conversion reaction and surface functionalization of nanostructured electrocatalysts. The N plasma treatment not only generates hierarchical nanostructure surface, but also induces N doping as well as hydrophilicity. Using C-plasma, we can partially reduce the metal oxide surface, and simultaneously deposit a thin and uniform carbon coating.
(2) We demonstrate that dual cation doping, or cation-anion co-doping can simultaneously modulate key parameters in water dissociation and hydrogen adsorption energies. As a result, the dopings lead to a significant enhancement in catalytic activities for both HER and OER. Recent result on atomic scale doping in 2D materials will also be presented.
(3) I will also present our achievements of effective bi-functional catalysts (ORR and OER) for cathode materials in Li-O2 and Zn air batteries.
Photocatalysis Using Earth-Abundant Copper-Based Plasmonic and High-Dielectric Nanostructures to Produce High-Value Chemicals
Authors: Addanki Tirumala Ravi Teja , Mohammadparast Farshid , Ramakrishnan Sundaram Bharadwaj , Andiappan Marimuthu 
Published: February 2020

Over the years plasmonic materials have received wide attention for their ability to convert solar into chemical energy. Plasmonic nanoparticles (NPs) exhibit strong electromagnetic-field (EMF) enhancement for the incident light because of the Localized Surface Plasmon Resonance (LSPR). This property has been shown to enhance the photocatalytic performance of nearby semiconductors in the composite, and hybrid photocatalysts build on plasmonic metal nanoparticle and semiconductor. In this presentation, we will focus on copper based hybrid plasmonic nanostructures and optically resonant high dielectric nanostructures for efficient conversion of solar into chemical energy.
Our FDTD simulation results predict that the EMF enhancement observed over high dielectric NPs are 2-3 orders of magnitude higher than the plasmonic NPs. This new family of non-plasmonic metal oxide nanostructures is dielectric in nature with high refractive index (> 2). Our simulation results predict that the Mie resonance over these high-dielectric nanostructures can be tuned anywhere from UV-Vis to the near-IR region by controlling the geometry of the nanostructures. We will also show experimental results that validate the simulation results. We utilized size and shape-controlled synthesis techniques to design optically resonant nanostructures with tunable Mie resonance. The optoelectronic properties of these nanostructures are confirmed using a number of spectroscopic techniques.
Also, we will show the visible-light enhanced photocatalytic performance of the high dielectric nanostructures for carbon-carbon (C-C) coupling reactions. The design rules developed for the optically resonant nanostructures in our study will potentially have a wide range of applications including the use of these nanostructures for solar-light driven photocatalysis and thin-film solar cell applications.
Computational Quest for High-Performance Electrocatalysts for Nitrogen Fixation
Authors: Chen Zhongfang , Zhao Jingxiang 
Published: February 2020

The nitrogen electroreduction reaction (NRR) in aqueous solutions at ambient conditions represents an attractive prospect to produce ammonia, but the development of long-term stable and low-cost catalysts with high-efficiency and high-selectivity remains a great challenge. Single-atom catalysts have emerged as a new frontier in heterogeneous catalysis, and demonstrated distinguishing performances for various reactions due to their high catalytic activity with a significantly reduced amount of metals used. The emerging metal-free catalysts for NRR have attracted increasing attention due to their intrinsic advantages, such as low cost, high reliability, good biocompatibility, and excellent sustainability
In this talk, we will present our recent efforts in designing single-atom and metal-free electrocatalysts to realize nitrogen reduction reaction (NRR) at ambient conditions. Besidesidentifying promising catalysts for N2fixation, we will emphasize the designing principles and the procedure in screening effective NRR catalysts based on the mechanism understanding.
(Invited) Solar Energy Conversion Enhanced By the Structure and Surface Improvements of Quaternary Semiconductors
Authors: Solarska Renata , Bienkowski Krzysztof , Jadwiszczak Michal , Dubiel Adrian 
Published: February 2020

Solar energy conversion with high yield and cost-effective ratio requires use of materials which are easily available, stable within the time and flexible in structure in order to allow improvements in their intrinsic and surface properties. A class of such materials are perovskites with ABO3 structure or kesterites. The basic structure of ABO3, has a high structural tolerance factor and can be maintained with a wide variety of constituent elements. As a result, the composition-property relationship can be systematically investigated while keeping the same crystal structure. Also, due to the exceptional stability of the structure, the valency, stoichiometry, and vacancy of perovskite compounds can be varied widely in order to tune optical, electrical and catalytic properties. Therefore, the challenge is to couple the synthetic approach with an expected outcome resulting from the theoretical calculations.
In this presentation we will show the study on quaternary Ln1-xNixTiO3 that revealed the optical and electronic properties might be affected by varying La content in the matrix under employment of a reductive atmosphere of H2. This constitutes a unique and advantageous feature for its use in solar energy conversion. Understanding the effect of La doping and Ni segregation occurring under the reductive atmosphere on the photoelectrochemical properties of the La1-xNixTiO3 will generate new set of knowledge while providing a facile route to tune photon absorption and charge transport properties. A similar study will be presented for kesterite Cu2ZnSnS4. The questions which will be undertaken are: does La doping favourably affect the electron-hole separation in addition to the enhancement of photon absorption?; how do oxygen vacancies created by ion doping and reduction in hydrogen affect the charge transport properties?; can Ni segregation affect the catalytic property of the Ln1-xNixTiO3 surface?. The same questions will be applied to kesterite based PEC system upon ion doping and applied atmosphere. We will try to answer these questions through use transient absorption spectroscopy approach allowing to follow changes in charge carrier dynamics from the sub nanoseconds up to seconds timescales upon introduction of any variable to the system.
Exploration of Vapor Electrolysis for Chemical Transformations
Authors: Fornaciari Julie C. , Zhou Jie , Bell Alexis T. , Weber Adam Z. 
Published: February 2020

Electrolytic devices provide a carbon-free option to producing hydrogen, with many advantages such as modular, scalable design and flexibility of operating parameters (temperature, pressure, etc.).1 Typically, electrolyzers are run under conditions that require a significant amount of clean, liquid water and are run at several A/cm2. However, the solar flux limits achievable current densities to ~100 mA/cm2 and furthermore the strong solar resources are oftentimes located in regions away from a ready supply of clean water. Finally, multiphase flow in electrolyzers also complicate the transport physics and reaction kinetics. These above challenges can be surmounted through the use of vapor electrolyzer, where water vapor is split to oxygen and hydrogen directly. Vapor electrolysis has not been extensively studied due to a limitation in how much water can be supplied to the system – water electrolysis is never mass-transport limited. Some studies have shown such a device2,3 but are more proof of concept. In this talk, we discuss an experimental diagnostic study of various parameters to increase the performance of such cells that can reach 1 A/cm2. In addition, using mathematical modeling we explore the various losses endemic to this system as well as its natural advantages to utilize impure water in arid or possibly marine climates. Finally, we will discuss how the understanding gained on vapor electrolysis and gas-diffusion electrodes can be transferred to the electrochemical conversion of other gases (e.g., methane, carbon dioxide, etc.). Preliminary findings of fuel electrochemical oxidation to partial oxidation products will be discussed.
Acknowledgements:
J.C.F. would like to thank Dr. Michael Gerhardt, Dr. Nemanja Danilovic, and Dr. Yagya Regmi for the helpful discussions. J.C.F. also acknowledges support from National Science Foundation Graduate Research Fellowship under Grant No. DGE 1106400. This work was partially funded by the Energy & Biosciences Institute through the EBI-Shell program.
References:

Carmo M., et. al. International Journal of Hydrogen Energy,Volume 38, Issue 12, 2013 .

Kistler T.A., et. al. Electrochem. Soc.volume 166, issue 5, 2019

Spurgeon J.M. , et. al. Energy Environ. Sci., 2011, 4, 2993-2998