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202 results on '"Wang, Tanyuan"'

7. Tailoring Zirconia Supported Intermetallic Platinum Alloy via Reactive Metal‐Support Interactions for High‐Performing Fuel Cells.

Author

Lin, Zijie, Sathishkumar, Nadaraj, Xia, Yu, Li, Shenzhou, Liu, Xuan, Mao, Jialun, Shi, Hao, Lu, Gang, Wang, Tanyuan, Wang, Hsing‐Lin, Huang, Yunhui, Elbaz, Lior, and Li, Qing

Subjects
PLATINUM alloys, PLATINUM, PROTON exchange membrane fuel cells, PLATINUM nanoparticles, FUEL cells, METALLIC oxides, ZIRCONIUM oxide, OXYGEN reduction, DENSITY functional theory
Abstract

Developing efficient and anti‐corrosive oxygen reduction reaction (ORR) catalysts is of great importance for the applications of proton exchange membrane fuel cells (PEMFCs). Herein, we report a novel approach to prepare metal oxides supported intermetallic Pt alloy nanoparticles (NPs) via the reactive metal‐support interaction (RMSI) as ORR catalysts, using Ni‐doped cubic ZrO2 (Ni/ZrO2) supported L10−PtNi NPs as a proof of concept. Benefiting from the Ni migration during RMSI, the oxygen vacancy concentrations in the support are increased, leading to an electron enrichment of Pt. The optimal L10−PtNi−Ni/ZrO2−RMSI catalyst achieves remarkably low mass activity (MA) loss (17.8 %) after 400,000 accelerated durability test cycles in a half‐cell and exceptional PEMFC performance (MA=0.76 A mgPt−1 at 0.9 V, peak power density=1.52/0.92 W cm−2 in H2−O2/−air, and 18.4 % MA decay after 30,000 cycles), representing the best reported Pt‐based ORR catalysts without carbon supports. Density functional theory (DFT) calculations reveal that L10−PtNi−Ni/ZrO2−RMSI requires a lower energetic barrier for ORR than L10−PtNi−Ni/ZrO2 (direct loading), which is ascribed to a decreased Bader charge transfer between Pt and *OH, and the improved stability of L10−PtNi−Ni/ZrO2−RMSI compared to L10−PtNi−C can be contributed to the increased adhesion energy and Ni vacancy formation energy within the PtNi alloy. [ABSTRACT FROM AUTHOR]

Published
2024
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12. Tuning the catalytic activity of graphene nanosheets for oxygen reduction reaction via size and thickness reduction

Author

Benson, John, Xu, Qian, Wang, Peng, Shen, Yuting, Sun, Litao, Wang, Tanyuan, Li, Meixian, and Papakonstantinou, Pagona

Subjects
Condensed Matter - Materials Science
Abstract

Currently, the fundamental factors that control the oxygen reduction reaction (ORR) activity of graphene itself, in particular the dependence of the ORR activity on the number of exposed edge sites remain elusive, mainly due to limited synthesis routes of achieving small size graphene. In this work, the synthesis of low oxygen content (< 2.5 +/-0.2 at %), few layer graphene nanosheets with lateral dimensions smaller than a few hundred nm was achieved using a combination of ionic liquid assisted grinding of high purity graphite coupled with sequential centrifugation. We show for the first time, that the graphene nanosheets possessing a plethora of edges exhibited considerably higher electron transfer numbers compared to the thicker graphene nanoplatelets. This enhanced ORR activity was accomplished by successfully exploiting the plethora of edges of the nanosized graphene as well as the efficient electron communication between the active edge sites and the electrode substrate. The graphene nanosheets were characterized by an onset potential of -0.13 V vs. Ag/AgCl and a current density of -3.85 mA/cm2 at -1 V, which represent the best ORR performance ever achieved from an undoped carbon based catalyst. This work demonstrates how low oxygen content nanosized graphene synthesized by a simple route can considerably impact the ORR catalytic activity and hence it is of significance in designing and optimizing advanced metal-free ORR electrocatalysts., Comment: corresponding author: p.papakonstantinou@ulster.ac.uk, ACS Applied Materials and Interfaces 2014

Published
2014
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20. Atomically dispersed Zn-Co-N-C catalyst boosting efficient and robust oxygen reduction catalysis in acid via stabilizing Co-N bonds

Author

Ma, Feng, Liu, Xuan, Wang, Xiaoming, Liang, Jiashun, Huang, Jianyu, Priest, Cameron, Liu, Jinjia, Jiao, Shuhong, Wang, Tanyuan, Wu, Gang, Huang, Yunhui, and Li, Qing

Abstract

Transition metal supported N-doped carbon (M-N-C) catalysts for oxygen reduction reaction (ORR) are viewed as the promising candidate to replace Pt-group metal (PGM) for proton exchange membrane fuel cells (PEMFCs). However, the stability of M-N-C is extremely challenging due to the demetalation, H2O2attack, etc. in the strongly oxidative conditions of PEMFCs. In this study, we demonstrate the universal effect of Zn on promoting the stability of atomically dispersed M-Nx/C (M = Co, Fe, Mn) catalysts and the enhancement mechanism is unveiled for the first time. The best-performing dual-metal-site Zn-Co-N-C catalyst exhibits a high half-wave potential (E1/2) value of 0.81 V vs.reversible hydrogen electrode (RHE) in acid and outstanding durability with no activity decay after 15,000 accelerated degradation test (ADT) cycles at 60 °C, surpassing most reported Co-based PGM-free catalysts in acid media. For comparison, the Co-N-C in the absence of Zn suffers from a rapid degradation after ADT due to the demetalation and higher H2O2yield. X-ray adsorption spectroscopy (XAS) and density functional theory (DFT) calculations suggest the more negative formation energy (by 1.2 eV) and increased charge transfer of Zn-Co dual-site structure compared to Co-N-C could strength the Co-N bonds against the demetalation and the optimized d-band center accounts for the improved ORR kinetics.

Published
2023
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25. A sodium-ion-conducted asymmetric electrolyzer to lower the operation voltage for direct seawater electrolysis.

Author

Shi, Hao, Wang, Tanyuan, Liu, Jianyun, Chen, Weiwei, Li, Shenzhou, Liang, Jiashun, Liu, Shuxia, Liu, Xuan, Cai, Zhao, Wang, Chao, Su, Dong, Huang, Yunhui, Elbaz, Lior, and Li, Qing

Subjects
SEAWATER, ELECTROLYSIS, SALINE water conversion, DENSITY functional theory, ACTIVATION energy, VOLTAGE, SOIL corrosion, ASYMMETRIC synthesis
Abstract

Hydrogen produced from neutral seawater electrolysis faces many challenges including high energy consumption, the corrosion/side reactions caused by Cl-, and the blockage of active sites by Ca2+/Mg2+ precipitates. Herein, we design a pH-asymmetric electrolyzer with a Na+ exchange membrane for direct seawater electrolysis, which can simultaneously prevent Cl- corrosion and Ca2+/Mg2+ precipitation and harvest the chemical potentials between the different electrolytes to reduce the required voltage. In-situ Raman spectroscopy and density functional theory calculations reveal that water dissociation can be promoted with a catalyst based on atomically dispersed Pt anchored to Ni-Fe-P nanowires with a reduced energy barrier (by 0.26 eV), thus accelerating the hydrogen evolution kinetics in seawater. Consequently, the asymmetric electrolyzer exhibits current densities of 10 mA cm−2 and 100 mA cm−2 at voltages of 1.31 V and 1.46 V, respectively. It can also reach 400 mA cm−2 at a low voltage of 1.66 V at 80 °C, corresponding to the electricity cost of US$1.36 per kg of H2 ($0.031/kW h for the electricity bill), lower than the United States Department of Energy 2025 target (US$1.4 per kg of H2). Hydrogen produced directly from neutral seawater is promising but challenging due to seawater's complex composition. Here, the authors report a Na+-conducted pH-asymmetric electrolyzer that can directly split seawater into hydrogen with low electricity cost and nearly zero chloride interference. [ABSTRACT FROM AUTHOR]

Published
2023
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32. Si Doping Enables Activity and Stability Enhancement on Atomically Dispersed Fe−Nx/C Electrocatalysts for Oxygen Reduction in Acid.

Author

Li, Shenzhou, Li, Zhiqiang, Huang, Tianping, Xie, Huan, Miao, Zhengpei, Liang, Jiashun, Pan, Ran, Wang, Tanyuan, Han, Jiantao, and Li, Qing

Subjects
OXYGEN reduction, ELECTROCATALYSTS, METAL catalysts, STANDARD hydrogen electrode, GRAPHITIZATION, HETEROGENEOUS catalysis, FUEL cells
Abstract

Fe−N−C represents the most promising non‐precious metal catalysts (NPMCs) for the oxygen reduction reaction (ORR) in fuel cells, but often suffers from poor stability in acid due to the dissolution of metal sites and the poor oxidation resistance of carbon substrates. In this work, silicon‐doped iron‐nitrogen‐carbon (Si/Fe−N−C) catalysts were developed by in situ silicon doping and metal–polymer coordination. It was found that Si doping could not only promote the density of Fe−Nx/C active sites but also elevated the content of graphitic carbon through catalytic graphitization. The best‐performing Si/Fe−N−C exhibited a half‐wave potential of 0.817 V vs. reversible hydrogen electrode in 0.5 m H2SO4, outperforming that of undoped Fe−N−C and most of the reported Fe−N−C catalysts. It also exhibited significantly enhanced stability at elevated temperature (≥60 °C). This work provides a new way to develop non‐precious metal ORR catalysts with improved activity and stability in acidic media. [ABSTRACT FROM AUTHOR]

Published
2023
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39. Oxygen Reduction: Biaxial Strains Mediated Oxygen Reduction Electrocatalysis on Fenton Reaction Resistant L1 0 ‐PtZn Fuel Cell Cathode (Adv. Energy Mater. 29/2020)

Author

Liang, Jiashun, primary, Zhao, Zhonglong, additional, Li, Na, additional, Wang, Xiaoming, additional, Li, Shenzhou, additional, Liu, Xuan, additional, Wang, Tanyuan, additional, Lu, Gang, additional, Wang, Deli, additional, Hwang, Bing‐Joe, additional, Huang, Yunhui, additional, Su, Dong, additional, and Li, Qing, additional

Published
2020
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40. Regulating Pd-catalysis for electrocatalytic CO2reduction to formate viaintermetallic PdBi nanosheets

Author

Xie, Linfeng, Liu, Xuan, Huang, Fanyang, Liang, Jiashun, Liu, Jianyun, Wang, Tanyuan, Yang, Liming, Cao, Ruiguo, and Li, Qing

Abstract

Electrocatalytic CO2reduction plays an important role in the reduction of the CO2concentration in atmosphere and consequently the mitigation of greenhouse effects. Pd has been extensively investigated as an electrocatalyst for the CO2reduction to formate, which is an important raw material in the production of organic chemicals. However, the low selectivity and competitive reaction (hydrogen evolution reaction (HER)) have hindered the performance of monometallic Pd catalysts. In this paper, intermetallic PdBi nanosheets (NSs) are prepared for efficient CO2reduction to formate. The highest Faradaic efficiency (FE) of formate on fully ordered PdBi NSs reaches 91.9% at −1.0 V vs. RHE, which outperforms that of the disordered PdBi and pure Pd catalysts. Density functional theory calculations suggest that compared to disordered PdBi NSs, the ordered structure can decrease the free energy barrier of *OCHO (a key intermediate of formate formation) and inhibit H2evolution as well, thereby enhancing the activity and selectivity for formate production.

Published
2022
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41. Bifunctional Atomically Dispersed Mo–N2/C Nanosheets Boost Lithium Sulfide Deposition/Decomposition for Stable Lithium–Sulfur Batteries

Author

Ma, Feng, primary, Wan, Yangyang, additional, Wang, Xiaoming, additional, Wang, Xinchao, additional, Liang, Jiashun, additional, Miao, Zhengpei, additional, Wang, Tanyuan, additional, Ma, Cheng, additional, Lu, Gang, additional, Han, Jiantao, additional, Huang, Yunhui, additional, and Li, Qing, additional

Published
2020
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42. Biaxial Strains Mediated Oxygen Reduction Electrocatalysis on Fenton Reaction Resistant L1 0 ‐PtZn Fuel Cell Cathode

Author

Liang, Jiashun, primary, Zhao, Zhonglong, additional, Li, Na, additional, Wang, Xiaoming, additional, Li, Shenzhou, additional, Liu, Xuan, additional, Wang, Tanyuan, additional, Lu, Gang, additional, Wang, Deli, additional, Hwang, Bing‐Joe, additional, Huang, Yunhui, additional, Su, Dong, additional, and Li, Qing, additional

Published
2020
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