High-entropy metal oxides (HEOs) are superior to many reactions involving multi-step elemental reactions, but the controlled synthesis of hollow-structured HEO catalysts with large surface area and fast mass transfer kinetics is still challenging and unexplored due to complex metal precursors. Based on this,Professor Kang Xiongwu of South China University of Technology and othersIn this paper, a hollow structure and polyhedral HEO catalyst assembled from ultra-small nanoparticles containing up to 10 metal elements is reported to be synthesized using an ion exchange method. The Znfenicucoru-O HEO catalyst exhibited excellent oxygen evolution reaction (OER) activity and superstability in the whole pH range, with an overpotential of 170 mV at a current density of 10 mA cm-2, a Tafel slope of 56 mV Dec-1, and an activity attenuation of 7% in alkaline media for 30 h, and attenuation of 12% and 8% in acidic and neutral media, respectively.
VASP Interpretation
By DFT calculations, the authors investigated the intrinsic active site of ZnfenicuCoru-O for OER. Typically, OER on metal oxide catalysts is performed by either the traditional adsorption evolution mechanism (AEM) or lattice oxygen evolution mechanism (LOM). The surface metal center serves as the catalytic active site, and the OH- ions in the solution undergo four proton-electron co-transfer steps to generate O2 in AEM. According to LOM, the O atom and lattice O in the OH- ion are involved in the OER, and oxygen vacancies are also formed during the reaction.
0. 086 V energy barrier, lower than 099 V, indicating that AEM is a more favorable route to OER on Znfenicuru-O. The high oxygen content adsorbed by ZnfenicuCoru-O greatly improves the adsorption capacity of oxygen-containing substances, which is conducive to the progress of AEM pathway. The potential barriers of the Ru-Fe bridge site are much lower than those of Ru-Ni and Ru-Co, indicating that OER is more inclined to the Ru-Fe bridge site that occurs on the catalyst surface. Fe, as the element with the highest atomic ratio in the catalyst, provides a large number of catalytically active sites for the AEM pathway of OER.
hollow-structured and polyhedron-shaped high entropy oxide towards highly active and robust oxygen evolution reaction in a full ph range. adv. mater.,, doi: ht-tps: