Empirical analysis and recent advances in metal-organic framework-derived electrocatalysts for oxygen reduction, hydrogen and oxygen evolution reactions

Developing ecofriendly electrocatalysts with high electrocatalytic performance is pivotal but remains a critical challenge in the efficient energy conversion technologies (including overall water splitting, hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR). Metal-organic framework (MOF)-derived electrocatalyst materials have become a rapidly rising research area for solving the challenges associated with energy conversion technologies. This is due to unique features of MOF materials such as unique composition, structural diversity, large surface area, tunability, highly porous nature, and the secondary building units. They are often crystalline, ordered, and uniform solids, which are beneficial to engineering valuable features in rational ways. These advantages over other electrocatalysts have enabled MOFs to be notably utilized to overcome the sluggish kinetics and intrinsic thermodynamic barriers. Based on this, numerous attention has been devoted to the employment of various MOFs in HER, OER, ORR and water splitting. However, a comprehensive dataset showing the empirical analysis of these electrocatalysts for these applications becomes necessary to understand how closer or farther to industrial/commercial applications. The realization of this will enable the development of novel electrocatalysts and electrolyte media to successfully overcome the intrinsic barriers of meeting the industrial and commercial expectations in the field. To efficiently describe this empirical analysis, this study started by presenting the value of data with the momentous needs and reasons for this analysis. Since the study uses the electrocatalytic performance of different MOF-derived electrocatalysts, different experimental parameters for evaluating the performance of these MOF-derived were described. It critically compares different MOF-derived electrocatalysts based on the mechanistic criteria for energy -conversion involving rate-determining steps (RDS) using Tafel, Heyrovsky, and Volmer slopes of-30,-40, and-120 mV/dec, respectively. The overpotential or half-wave potential of these catalysts was also evaluated for further recommendations. A borderline of 50 h stability tests was drawn to gain more insight into the stability/durability performance and prospects of MOF-derived materials for HER, OER and ORR, which reflects that many of these materials performed below 50 h steady-state (durability) tests. This study further discussed some features of stability and stability under electrochemical conversion conditions. Also, in term of electrolytes for research on energy conversion, 1 M KOH, 0.1 M KOH, 0.5 M H2SO4, and 1 M KOH were prevalent, accounting for 73.53%, 88.24%, 58.49%, and 67.39% for OER, ORR, HER, and overall water splitting, respectively. To corroborate the empirical analysis, an overview of recent development on the electrocatalytic MOF-derived materials for HER, OER, and ORR was also discussed. Finally, the prospect of commercializing the MOF-derived electrocatalysts, the way forward in electrocatalysis, challenges and knowledge gap were discussed.