Toward Electrocatalytic Methanol Oxidation Reaction: Longstanding Debates and Emerging Catalysts.

The study on direct methanol fuel cells (DMFCs) has lasted around 70 years since its first investigation in the early 1950s. Though enormous effort has been devoted in this field, it is still far from commercialization. The methanol oxidation reaction (MOR) as a semi-reaction of DMFCs is the bottleneck reaction that restricts the overall performance of DMFCs. To date, there are intense debates on the complex 6-electron reaction, but barely any reviews have systematically discussed this topic. To this end, we summarized the controversies and progress regarding the electrocatalytic mechanisms, performance evaluations as well as the design science toward MOR electrocatalysts. This review also provides a comprehensive introduction on the recent development of emerging MOR electrocatalysts with a focus on the innovation of the alloy, core-shell structure, heterostructure and single-atom catalysts. Finally, perspectives on the future outlook toward the mechanisms study and electrocatalysts design are provided. This article is protected by copyright. All rights reserved.