Insights into in Situ Surface Reconstruction in Cobalt Perovskite Oxides for Enhanced Catalytic Activity

作     者：Jin, Yanyu Cheng, Hongjun Wang, Qibao Liu, Xiaoqing Mo, Shengpeng Zhou, Bin Peng, Yue Wang, Yu Si, Wenzhe Li, Junhua 

作者机构：School of Environmental Science and Engineering Yancheng Institute of Technology Yancheng224051 China State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing100084 China School of Environment and Safety Engineering North University of China Taiyuan030051 China School of Chemical & Environmental Engineering China University of Mining and Technology Beijing100084 China 

出 版 物：《SSRN》 

年 卷 期：2024年

核心收录：

主　　题：Perovskite 

摘      要：An depth understanding of the fundamental interactions between surface termination and catalytic activity is crucial to prompt the properties of functional perovskite materials. The elastic energy due to size mismatch and electrostatic attraction of the charged Sr dopant by positively charged oxygen vacancies induced inert A-site surface enrichment rearrangement for perovskites . Lower temperatures could reduce A-site enrichment, but it is difficult to form perovskite crystals. La0.8Sr0.2CoO3-δ (LSCO) as a model perovskite oxide was modified with additive urea to reduce the crystallization temperature, and suppress Sr segregation. The LSCO catalysts with 600°C annealing temperature (LSCO-600) exhibited a 19.4-fold reaction reactivity of toluene oxidation than that with 800°C annealing temperature (LSCO-800). Combined surface-sensitive and depth-resolved techniques for surface and sub-surface analysis, surface Sr enrichment was effectively suppressed due to decreased oxygen vacancy concentration and smaller electrostatic driving force. DFT calculations and in-situ DRIFTS spectra well reveal that tuning the surface composition/termination affects the intrinsic reactivity. The catalyst surface with lower Sr enrichment could easily adsorb toluene, cleave, and decompose benzene rings, thus contributing to toluene degradation to CO2. This work demonstrates a green and efficient way to control surface composition and termination at the atomic scale for higher catalytic activity. © 2024, The Authors. All rights reserved.