High entropy oxides-exploring a paradigm of promising catalysts: A review

Abstract

This review presents the structural elements and discusses the great potential of high entropy oxides (HEO) as promising catalysts. A critical comparison is provided with the medium and low entropy metal oxides in terms of the important functionality of HEO to exhibit higher oxygen mobility and withhold high population of oxygen vacancies as well as leading to high metal dispersion. This review study critically compares the performance of the thermal, electro- and photo- high entropy oxides catalysts with the conventional metal oxides and demonstrates their superiority over them while discussing the governing characteristics of HEO. The HEO complex structure is highlighted using ab initio calculations on understanding and tuning their electronic/structural properties. Catalysts’ design criteria and direction in the studies of the HEO as catalysts for energy and sustainability are proposed. © 2021 The Authors