摘要
Complex metal oxide has emerged as an important class of electrocatalyst for oxygen evolution reaction(OER)because of its flexibility in the crystal phase and relative ease in the control of defect structures.While different crystalline phases and solid structures may be produced from the same reactant precursors,their phase transitions and OER performances are not well understood.In this work,we present the preparation of different phases of SrCo_(0.9)Fe_(0.1)O_(3-δ)(nominal ratio)solids using a sol-gel method and the structure-catalytic property relationship of both crystalline and amorphous structures formed at different temperatures.We observed as synthetic temperature increased,phase and composition transitions occurred from the amorphous phase to strontium carbonate and cobalt oxide,to oxygen-deficient perovskite,and finally to perovskite.The OER activity depended highly on crystal structures.The oxygen-deficient perovskite prepared at 750℃ exhibited the highest catalytic activity,while the perovskite showed the lowest activity.X-ray photoelectron spectroscopy analysis reveals the change of oxidation state occurred during the phase transition.This work provides a useful guideline for the design of OER electrocatalysts through controlling the crystal structures and defects in complex metal oxides,such as perovskite.
出处
《SusMat》
2022年第4期445-455,共11页
可持续发展材料（英文）
基金
This research was supported in part by the US National Science Foundation(NSF-2055734)and a start-up fund from University of Illinois at Urbana-Champaign.F.F.Wang was grateful for the support of a scholarship from the China Scholarship Council(CSC).M.Batool was funded by a fellowship from the Higher Education Commission of Pakistan(HEC).The X-ray diffraction was carried out at the George L.Clark X-ray Facility and 3M Material Laboratory,School of Chemical Science at UIUC.Other structural characterizations were performed at the Materials Research Laboratory at UIUC.
