Progressivity in Oxygen Evolution Electrocatalysis: An Unheeded Paradigm

Abstract Sustainable production and an environmentally conscious approach are at the forefront of scientists' considerations in addressing the increasing energy demand. The production of H 2 , an energy carrier that can store and transport energy, from water by electrolysis has been considered a promising energy solution. Nonetheless, the oxygen evolution reaction (OER) constrains the overall cell efficiency. Indeed, the persistent performance of a catalyst in repeated or prolonged applications is dreamt. Most of the research mainly focused on the OER catalytic performance. However, there is a lack of comprehensive evaluations of in‐situ OER performance, especially studies that analyze the catalyst after a certain period to clarify the underlying mechanisms. Consequently, the significant benefits of the gradual enhancement in catalytic performance during electrochemical OER have seldom been explored. This study evolved the new concept of catalytic progressivity as an unheeded arena benefiting sustainable H 2 energy solutions. This discussion highlights improved durability and exceptional OER selectivity of a catalyst with the timespan of operation. Elucidation of the reasons behind the progressive enhancement of OER activity, along with the rediscovering the potential materials and external stimuli like temperature, magnetic field, etc., modulating progressivity are discussed. This novel concept of progressivity is developed by highlighting common aspects of OER electrocatalysis reported and would advance the water splitting field for producing H 2 energy.