Recent progress and perspective on electrocatalysis in neutral media: Mechanisms, materials, and advanced characterizations

Abstract

Electrocatalysis, which involves oxidation and reduction reactions with direct electron transfer, is essential for a variety of clean energy conversion devices. Currently, the vast majority of studies regarding electrocatalysis reactions focus on strong acidic or alkaline media because of the higher catalytic activity. Nevertheless, some inherent drawbacks, including the corrosive environment, expensive proton exchange membranes, and side effects, are still hard to break through. A sustainably promising way to overcome these shortcomings is to deploy neutral/near-neutral electrolytes for electrocatalysis reactions. Unfortunately, insufficient research in this area due to the lack of attention to related issues has slowed down the development process. In this review, we systematically review the catalytic reaction mechanisms, neutral electrolytes, electrocatalysts, and modification strategies carried out in neutral media on the three most common electrocatalytic reactions, that is, hydrogen evolution reaction, oxygen reduction reaction, and oxygen evolution reaction. Furthermore, the advanced characterization tools for guiding catalyst synthesis and mechanistic studies are also summarized. Eventually, we propose some challenges and perspectives on electrocatalysis reactions in neutral media and hope it will attract more research interest and provide guidance in neutral electrocatalysis.