Browsing by Author "Ran, R"

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    Bulk and surface properties regulation of single/double perovskites to realize enhanced oxygen evolution reactivity
    (John Wiley & Sons, Inc, 2020-04-06) Sun, HS; Hu, B; Guan, DQ; Hu, ZW; Fei, LS; Li, MR; Peterson, VK; Lin, HJ; Chen, CT; Ran, R; Zhou, W; Shao, ZP
    Perovskite-based oxides have emerged as promising oxygen evolution reaction (OER) electrocatalysts. The performance is closely related to the lattice, electronic, and defect structure of the oxides, which determine surface and bulk properties and consequent catalytic activity and durability. Further, interfacial interactions between phases in a nanocomposite may affect bulk transportation and surface adsorption properties in a similar manner to phase doping except without solubility limits. Herein, we report the development of a single/double perovskite nanohybrid with limited surface self-reconstruction capability as an OER electrocatalyst. Such superior performance arises from a structure that maintains high crystallinity post OER catalysis, in addition to forming an amorphous layer following the self-reconstruction of a single perovskite structure during the OER process. In situ X-ray absorption near edge structure spectroscopy and high-resolution synchrotron-based X-ray diffraction reveal an amorphization process in the hybrid single/double perovskite oxide system that is limited in comparison to single perovskite amorphization, ensuring high catalytic activity. © 2020 Wiley-VCH Verlag GmbH & Co
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    High-performance perovskite composite electrocatalysts enabled by controllable interface engineering
    (John Wiley & Sons, Inc, 2021-06-17) Xu, XM; Pan, YL; Ge, L; Chen, YB; Mao, X; Guan, DQ; Li, MR; Zhong, YJ; Hu, ZW; Peterson, VK; Saunders, M; Chen, CT; Zhang, HJ; Ran, R; Du, AJ; Jiang, SP; Zhou, W; Shao, ZP
    Single-phase perovskite oxides that contain nonprecious metals have long been pursued as candidates for catalyzing the oxygen evolution reaction, but their catalytic activity cannot meet the requirements for practical electrochemical energy conversion technologies. Here a cation deficiency-promoted phase separation strategy to design perovskite-based composites with significantly enhanced water oxidation kinetics compared to single-phase counterparts is reported. These composites, self-assembled from perovskite precursors, comprise strongly interacting perovskite and related phases, whose structure, composition, and concentration can be accurately controlled by tailoring the stoichiometry of the precursors. The composite catalyst with optimized phase composition and concentration outperforms known perovskite oxide systems and state-of-the-art catalysts by 1–3 orders of magnitude. It is further demonstrated that the strong interfacial interaction of the composite catalysts plays a key role in promoting oxygen ionic transport to boost the lattice-oxygen participated water oxidation. These results suggest a simple and viable approach to developing high-performance, perovskite-based composite catalysts for electrochemical energy conversion. © 2021 Wiley-VCH GmbH
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    In operando‐formed interface between silver and perovskite oxide for efficient electroreduction of carbon dioxide to carbon monoxide
    (Wiley, 2023-04) Wu, XH; Guo, Y; Gu, Y; Xie, F; Li, M; Hu, Z; Lin, HJ; Pao, CW; Huang, YC; Dong, CL; Peterson, VK; Ran, R; Zhou, W; Shao, ZP
    Electrochemical carbon dioxide (CO2) reduction (ECR) is a promising technology to produce valuable fuels and feedstocks from CO2. Despite large efforts to develop ECR catalysts, the investigation of the catalytic performance and electrochemical behavior of complex metal oxides, especially perovskite oxides, is rarely reported. Here, the inorganic perovskite oxide Ag‐doped (La0.8Sr0.2)0.95Ag0.05MnO3–δ (LSA0.05M) is reported as an efficient electrocatalyst for ECR to CO for the first time, which exhibits a Faradaic efficiency (FE) of 84.3%, a remarkable mass activity of 75 A g−1 (normalized to the mass of Ag), and stability of 130 h at a moderate overpotential of 0.79 V. The LSA0.05M catalyst experiences structure reconstruction during ECR, creating the in operando‐formed interface between the perovskite and the evolved Ag phase. The evolved Ag is uniformly distributed with a small particle size on the perovskite surface. Theoretical calculations indicate the reconstruction of LSA0.05M during ECR and reveal that the perovskite–Ag interface provides adsorption sites for CO2 and accelerates the desorption of the *CO intermediate to enhance ECR. This study presents a novel high‐performance perovskite catalyst for ECR and may inspire the future design of electrocatalysts via the in operando formation of metal–metal oxide interfaces. © 2022 The Authors. Carbon Energy published by Wenzhou University and John Wiley & Sons - Open Access CC BY 4.0