The ion effect on the electrocatalytic oxidation reactions

Abstract

The electrode/electrolyte interface has a profound impact on the chemical environment of electrocatalysis. Specifically, changing the type or concentration of ions in the electrolyte composition may modulate the activity and selectivity of the target product, which is often called the ion effect. The cation effect has been widely recognized for greatly impacting the cathodic reactions, such as hydrogen evolution reaction and carbon dioxide reduction reaction. The ion effect for anodic reactions has been, comparatively, less studied. However, owing to the significant contribution of anodic reactions on the overall efficiency of electrolytic systems and emerging interest in synthetic electrochemistry, researchers have revived the interest in exploring the ion effect on anodic reactions. In this review, we will summarize the recent progresses on the anodic ion effect. The reactions will span from the widely-studied oxygen evolution reaction under different pHs, alcohol oxidation and even to electro-synthetic reactions. The ion effect on the activity and selectivity will be outlined, from which the general principles and influencing mechanisms will be clarified. Through the summary of the anodic ion effect, we will eventually propose the challenges and prospects for the general ion effect and their wide applications in electrocatalysis.