Recent status and challenging perspective of high entropy oxides for chemical catalysis

High entropy oxides (HEOs) have attracted wide interest for chemical catalysis owing to abundant active sites, adjustable specific surface area, stable crystal structure, extraordinary geometric compatibility, and unique electronic balance factors, exhibiting huge potential value for commercial exploitation. Here, the recent progress and current challenges of HEOs from the typical synthetic strategies, unique structural features, and intrinsic properties to applications in both thermocatalysis and electrocatalysis are comprehensively summarized. In brief, the HEOs obtained by different synthetic strategies, along with their structural features and derived physical-chemical properties endowed by the entropy-driven effect, allow them with highly efficient catalytic application performance. More important, the remarkable enhancement of catalytic performance based on the pure and modified HEOs are discussed by analyzing reaction mechanisms to further motivate the development in this emerging field. Finally, the future directions and challenging perspectives for chemical catalysis over HEOs are also put forward. The development of materials science and catalysis technology plays a significant role in promoting human and social progress. The catalytic utilization of high entropy materials (HEMs) has attracted intense attention for chemical catalysis because of their superior thermostability and variable chemical properties. In particular, the high entropy oxides (HEOs) demonstrate huge potential for thermocatalytic and electrocatalytic applications. Modifying HEOs catalysts for targeted reactions would be a promising technical step toward the development of materials science and catalysis technology. Moreover, HEOs also have been confirmed to be active for many thermocatalysis (heterogeneous and homogeneous) fields, electrocatalysis fields, and energy storage applications. This review summarizes the recent developments and challenging perspectives of HEOs for chemical catalysis, which are of great importance to guide the future directions of emerging HEO-based catalysis. High entropy oxides (HEOs) have attracted wide interest for chemical catalysis owing to abundant active sites, adjustable specific surface area, stable crystal structure, extraordinary geometric compatibility, and unique electronic balance factors, exhibiting huge potential value for commercial exploitation. Here, the recent progress and current challenges of HEOs from the typical synthetic strategies, unique structural features, and intrinsic properties to applications in both thermocatalysis and electrocatalysis are comprehensively summarized. In brief, the HEOs obtained by different synthetic strategies, along with their structural features and derived physical-chemical properties endowed by the entropy-driven effect, allow them with highly efficient catalytic application performance. More important, the remarkable enhancement of catalytic performance based on the pure and modified HEOs are discussed by analyzing reaction mechanisms to further motivate the development in this emerging field. Finally, the future directions and challenging perspectives for chemical catalysis over HEOs are also put forward.