Article
Materials Science, Multidisciplinary
Zifang Cheng, Yecan Pi, Qi Shao, Xiaoqing Huang
Summary: Researchers successfully prepared boron-doped amorphous iridium oxide catalyst with ultra-high OER mass activity, demonstrating the effectiveness of boric acid in enhancing the activity of iridium catalysts. The reported strategy is universal and can be applied to improve other metal oxide catalysts, indicating a versatile approach for creating high-performance electro-catalysts for various applications.
SCIENCE CHINA-MATERIALS
(2021)
Article
Engineering, Environmental
Lu-Yu Chueh, Chun-Han Kuo, Ding-Huei Tsai, Meng-Hsuan Tsai, Han-Yi Chen, Chia-Hsin Wang, Yung-Tin Pan
Summary: The ultra-fine iridium nanocatalyst is successfully dispersed and stabilized on sub-stoichiometric tungsten oxide nanowires, forming an active and stable OER catalyst. The WOxNW supported Ir catalyst exhibits a high mass activity of 812 A/gIr, which is significantly higher than other catalysts. The strong catalyst-support interaction contributes to the excellent stability and maintenance of the OER active structure.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Danilo Gonzalez, Mariona Sodupe, Luis Rodriguez-Santiago, Xavier Solans-Monfort
Summary: H-2 production through water electrolysis is a promising strategy for storing sunlight energy. Iridium oxide containing materials are the state-of-the-art for the oxygen evolution reaction, with small nanoparticles showing high catalytic activities. This study performed DFT calculations to determine the factors controlling the catalytic activity of IrO2 nanoparticles.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Physical
Kyuho Lee, Raul A. Flores, Yunzhi Liu, Bai Yang Wang, Yasuyuki Hikita, Robert Sinclair, Michal Bajdich, Harold Y. Hwang
Summary: This study demonstrates the growth of alpha-IrO2 epitaxial thin films using pulsed laser deposition, showing that crystal orientation significantly affects the electrocatalytic activity. The results suggest that epitaxial thin film growth can overcome energetic instabilities and provide unique opportunities to effectively determine the atomic structure of active catalysts.
ACS APPLIED ENERGY MATERIALS
(2021)
Article
Chemistry, Physical
Dasol Jin, Hyomin Yoo, Youngmi Lee, Chongmok Lee, Myung Hwa Kim
Summary: In this study, an IrO2-ZnO composite nanorod array with distinct morphological features was successfully fabricated. It exhibited superior OER catalytic activities and robust long-term cycling stability. This synthetic methodology provides a promising strategy for preparing highly efficient Zn-mixed metal oxides as electrocatalysts.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Green & Sustainable Science & Technology
Dandan Wu, Xi Wang, Zixuan Wang, Xu Wu
Summary: The development of highly active and stable anodes for oxygen evolution reaction (OER) in acidic media is still a challenge. In this study, a two-step electrodeposition method was proposed to optimize the structure of IrOx electrode for improved OER performance. The optimized electrode showed low Tafel slope, low overpotential, and good stability.
MATERIALS TODAY SUSTAINABILITY
(2023)
Article
Engineering, Environmental
Xiaojie Chen, Weimo Li, Na Song, Mengxiao Zhong, Su Yan, Jiaqi Xu, Wendong Zhu, Ce Wang, Xiaofeng Lu
Summary: This study reports on the enhancement of the OER performance of iridium oxides in an acidic electrolyte through the introduction of molybdenum. The prepared IrMoOx nanofibers show superior OER activity and long-term stability compared to bare IrOx and MoOx, as well as a benchmark commercial catalyst. Furthermore, an overall water splitting device assembled with IrMoOx and Pt/C electrodes exhibits improved performance and stability.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Physical
Hong Lv, Yongwen Sun, Sen Wang, Wenxuan Ji, Wei Zhou, Cunman Zhang
Summary: The study demonstrates the synthesis and application of low-cost and highly efficient catalysts for the oxygen evolution reaction (OER) through N/C doped amorphous iridium oxide. The catalytic activity of the iridium oxide catalyst is enhanced by its structure and chemical state. The N/C doped amorphous iridium oxide catalyst exhibits a lower cell voltage and maintains high current density for over 200 hours, providing a promising method for improving OER electrocatalysts and constructing efficient and stable PEM water cracking systems.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Multidisciplinary
Xiao Liang, Wensheng Yan, Yinglong Yu, Kexin Zhang, Wei An, Hui Chen, Yongcun Zou, Xiao Zhao, Xiaoxin Zou
Summary: Improving catalytic activity without compromising catalytic stability is a core goal in the search for low-iridium-content oxygen evolution electrocatalysts under acidic conditions. In this study, a family of SrBO3 perovskite oxides with different Ti : Ru : Ir atomic ratios was synthesized, and catalytic activity-stability maps were constructed. These maps classify the multicomponent perovskites into chemical groups with distinct catalytic activity and stability, highlighting a chemical region where high catalytic activity and stability are achieved simultaneously at a relatively low iridium level.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Gaoyang Liu, Faguo Hou, Xingdong Wang, Baizeng Fang
Summary: Researchers have developed an effective strategy to construct a unique heterogeneous interface between Ir nanoclusters and IrO2, resulting in an Ir-IrO2 catalyst with improved catalytic activity and durability for the oxygen evolution reaction (OER). The Ir-IrO2 catalyst exhibited increased catalytic active sites and enhanced catalytic activity compared to pure IrO2 and commercial IrO2.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Yi Wang, Guichan Chen, Jiao Xie, Dengjie Chen
Summary: This study demonstrates a simple non-metal/metalloid modification method to create efficient electrocatalysts for the oxygen evolution reaction (OER). The developed SrCo0.95M0.05O3_$ catalysts show lower overpotential and improved stability compared to the traditional SrCoO3_ $. The findings provide a simple and viable strategy for creating highly efficient perovskite electrocatalysts for OER.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Ji Yang, Cheng-long Ma, Lin Zhu, Li-mei Cao
Summary: Two iridium-based crystal structures, K0.3IrO2 center dot xH2O and Rb0.3IrO2 center dot xH2O, were synthesized for application in the oxygen evolution reaction (OER). The increase of oxygen vacancy concentration caused by lattice distortion in the 3R-IrO2 crystal is negatively correlated with the activity of OER. The 3R-IrO2 crystal is not thermodynamically stable and not suitable for hydrogen production by electrolysis of water.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Chemistry, Physical
Xiaojie chen, Wenying Liao, Mengxiao Zhong, Junjie Chen, Su Yan, Weimo Li, Ce Wang, Wei Chen, Xiaofeng Lu
Summary: By electrospinning and relatively low-temperature calcination, we designed and prepared Ir-CeO2-C nanofibers for OER application in both alkaline and acidic conditions. Density functional theory simulations demonstrated the high catalytic active sites of Ir atoms, and the formation of Ir-0 bonds at the interface between Ir and CeO2 can promote the OER activity. Additionally, the unique nanofibrous heterostructure increased the exposed active sites and promoted the electrical conductivity.
Article
Chemistry, Physical
Xiaojie Chen, Wenying Liao, Mengxiao Zhong, Junjie Chen, Su Yan, Weimo Li, Ce Wang, Wei Chen, Xiaofeng Lu
Summary: This research presents an efficient means to design OER catalysts with superior properties in both alkaline and acidic solutions. The prepared Ir-CeO2-C nanofibrous catalyst delivers excellent OER property in both alkaline and acidic solutions, with low overpotentials and favorable long-term stability. The nanofibrous heterostructure increases the exposed active sites and promotes electrical conductivity.
Article
Chemistry, Physical
Tsutomu Ioroi, Tsukasa Nagai, Zyun Siroma, Kazuaki Yasuda
Summary: This study investigates the parameters of the rotating disk electrode (RDE) that affect the activity evaluations for the oxygen evolution reaction (OER). Various iridium catalysts are used to examine the impacts of RDE parameters on the measured OER activity in order to obtain the activation polarization accurately. The potential range, catalyst loading, and anions in the electrolyte are found to have a significant impact on the catalytic activity. Comparison of the OER activities of the optimized RDE conditions with those determined using a labo-scale electrolyzer test cell and membrane and electrode assembly (MEA) show consistent results, indicating that the RDE half-cell with proper evaluation conditions can be a useful and rapid initial catalyst screening method to estimate the OER activity in the MEA.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Multidisciplinary
Michael R. R. Smith, Clare B. B. Martin, Sonia Arumuganainar, Ari Gilman, Bruce E. E. Koel, Michele L. L. Sarazen
Summary: Immobilization of porphyrin complexes into metal-organic frameworks enables high exposure of active sites for CO2 electroreduction. Well-dispersed iron-porphyrin-based MOF (PCN-222(Fe)) on carbon-based electrodes showed optimal turnover frequencies for CO2 reduction to CO. In situ Raman spectroscopy revealed the structure stability of PCN-222(Fe) and a stepwise electron transfer-proton transfer mechanism for CO2 electroreduction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Lotanna Ezeonu, Ziyu Tang, Yue Qi, Fangliang Huo, Yiteng Zheng, Bruce E. Koel, Simon G. Podkolzin
Summary: Acetic acid adsorption and surface reactions were studied on Pt(111) and Ni(110) using IRAS and temperature programmed desorption. The results showed that acetic acid forms a chemisorbed layer and a physisorbed multilayer on both metals. At 200K, acetic acid decomposes almost completely on Pt but produces some CO on Ni. At 450K, acetic acid decomposition is almost complete on both metals. Ni has lower catalytic activity in hydrodeoxygenation due to its lower reducibility.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Physical
Ziyu Wang, Chao Yan, Bowen Mei, Ying Lin, Yiguang Ju
Summary: This study investigates the oxidation of diethyl ether (DEE) under low-temperature and ultra-high-pressure conditions. The experimental data shows that DEE exhibits unusual low-temperature oxidation behavior with two negative temperature coefficient (NTC) zones. Increasing the pressure stabilizes RO2 and promotes HO2 chemistry, resulting in weaker NTC zones. The existing DEE model is updated to improve the predictability of key species, especially at intermediate temperature.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Multidisciplinary Sciences
Bo Wen, Marcos F. Calegari Andrade, Li-Min Liu, Annabella Selloni
Summary: In this study, the interaction between water and the TiO2(110) surface was investigated using molecular dynamics simulations. It was found that the equilibrium fraction of water dissociation at the TiO2(110) interface is 22 +/- 6%. This result suggests that the TiO2(110) interface has higher water photooxidation activity compared to the TiO2(101) interface.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Physics, Multidisciplinary
P. S. Krstic, E. T. Ostrowski, S. Dwivedi, A. Maan, S. Abe, A. C. van Duin, B. E. Koel
Summary: By using atomistic computational methods, the sputtering, reflection, and retention processes on amorphous and crystalline lithium hydride surfaces under the impact of low energy (1-100 eV) hydrogen and deuterium atoms were investigated. Classical molecular dynamics simulations were performed with improved reactive bond-order force field (ReaxFF) potentials, which include long-range polarization effects. The study revealed the importance of hydrogen saturation on the surface and near-surface region of the Li material, and how it significantly affects the surface processes under low-energy hydrogen irradiation.
FRONTIERS IN PHYSICS
(2023)
Article
Chemistry, Physical
Zhihong Wu, Wen-Jin Yin, Bo Wen, Dongwei Ma, Li-Min Liu
Summary: In this study, a deep neural network model was trained using an active learning method based on ab initio data of a defective TiO2 surface. The deep potentials (DPs) obtained from the model showed good consistency with density functional theory (DFT) results. The DPs were then applied to simulate the behavior of oxygen vacancies on the extended surface, revealing their stability and diffusion barriers. These findings demonstrate that machine-learning trained DPs can accelerate molecular dynamics with DFT-level accuracy and enhance our understanding of fundamental reactions at the microscopic level.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Physics, Applied
P. S. Krstic, E. T. Ostrowski, S. Dwivedi, S. Abe, A. Maan, A. C. T. van Duin, B. E. Koel
Summary: This research uses computational physics and chemistry modeling to study the evolving characteristics of materials in the plasma-material interfaces, focusing on lithium, oxygen, and hydrogen-containing materials under hydrogen irradiation. The study reveals the critical role of charging dynamics of lithium, oxygen, and hydrogen atoms in driving surface chemistry and its potential impact on fusion plasma confinement behavior and surface erosion.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Chemistry, Physical
Zhutian Ding, Annabella Selloni
Summary: In this study, a model of the a-TiO2 surface was constructed using molecular dynamics simulations and deep neural network potentials trained on density functional theory data. The structure and dynamics of the a-TiO2-water interface were investigated using a combination of DP-based molecular dynamics and ab initio molecular dynamics simulations. The results revealed that the water distribution on the a-TiO2 surface lacks distinct layers, leading to faster diffusion of water at the interface. The study also found that bridging hydroxyls decay slower than terminal hydroxyls due to fast proton exchange events.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Christopher R. O'Connor, Marcos F. Calegari Andrade, Annabella Selloni, Greg A. Kimmel
Summary: The adsorption structure of water on the (101) surface of TiO2 has been investigated, revealing the formation of one-dimensional chains and a two-dimensional hydrogen bond network. This structural motif is likely to persist under ambient conditions and have significant implications for surface reactions.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Weijie Lin, Wen-Jin Yin, Bo Wen
Summary: In this study, the catalytic activity of hydrogen evolution reaction at different site distances in single-atom catalysts was systematically investigated using density functional theory calculations. The results revealed the importance of the proximity effect between adjacent sites in enhancing catalytic activity. By analyzing the electronic properties, it was found that the proximity effect is caused by the difference in net charge between different active sites, and an electron nodal channel was identified as the pathway for communication between active sites.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Taehun Lee, Annabella Selloni
Summary: In this work, the electronic states and energy levels of oxygen vacancies and n-type dopants in m-ZrO2 were characterized using accurate dielectric-dependent hybrid functional calculations. The results reveal that oxygen vacancies generally behave as deep donors in m-ZrO2, and the excess electrons are localized at the vacant oxygen sites. Surface oxygen vacancies at two-fold coordinated oxygen sites exhibit a rather shallow (1+/0) transition level. Adsorbed hydrogen and fluorine substituting an oxygen atom show shallow levels, while niobium and tantalum form deep levels. Overall, fluorine substituting an oxygen atom is the best candidate for achieving n-type conductivity in bulk m-ZrO2, while surface oxygen vacancies and adsorbed hydrogen provide an efficient way to control the surface chemistry of m-ZrO2.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Abhinav S. Raman, Annabella Selloni
Summary: This study investigates the hydration structure, proton transfer mechanisms, and acid-base properties of the rutile IrO2(110)-water interface using ab initio based deep neural-network potentials and enhanced sampling simulations. The proton affinities of different surface sites are characterized, and a point of zero charge is obtained. Results show a large fraction of adsorbed water dissociation and a short lifetime of resulting hydroxy groups due to rapid surface proton exchanges, supporting recent experimental findings that the rate-determining step in the oxygen evolution reaction may not involve proton transfer into solution.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Instruments & Instrumentation
Shota Abe, Bruce E. Koel
Summary: This study reports the ion flux concentration ratios for various ion species in an ion beam generated by a commercially available electron cyclotron resonance plasma source. The results provide valuable information for research on plasma-material interactions.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Chemistry, Physical
Dawei Deng, Rutong Si, Bo Wen, Nicola Seriani, Xiao-Lin Wei, Wen-Jin Yin, Ralph Gebauer
Summary: In this study, the structural and electronic properties of polar GaN/MoSSe heterostructures were investigated using first-principles calculations. It was found that a self-doped p-n junction can be achieved by modifying the band alignment, leading to high carrier concentrations. This behavior can be attributed to charge redistribution and the intrinsic electric field induced by polarization, causing shifts in the band edge positions and the induction of the quantum Stark effect.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
