Ultrathin NiV Layered Double Hydroxide for Methanol Electrooxidation: Understanding the Proton Detachment Kinetics and Methanol Dehydrogenation Oxidation

Abstract

AbstractElectrochemical methanol oxidation reaction (MOR) is regarded as a promising pathway to obtain value‐added chemicals and drive cathodic H2 production, while the rational design of catalyst and in‐depth understanding of the structure‐activity relationship remains challenging. Herein, the ultrathin NiV‐LDH (u‐NiV‐LDH) with abundant defects is successfully synthesized, and the defect‐enriched structure is finely determined by X‐ray adsorption fine structure etc. When applied for MOR, the as‐prepared u‐NiV‐LDH presents a low potential of 1.41 V versus RHE at 100 mA cm−2, which is much lower than that of bulk NiV‐LDH (1.75 V vs RHE) at the same current density. The yield of H2 and formate is 98.2% and 88.1% as its initial over five cycles and the ultrathin structure of u‐NiV‐LDH can be well maintained. Various operando experiments and theoretical calculations prove that the few‐layer stacking structure makes u‐NiV‐LDH free from the interlayer hydrogen diffusion process and the hydrogen can be directly detached from LDH laminate. Moreover, the abundant surface defects upshift the d‐band center of u‐NiV‐LDH and endow a higher local methanol concentration, resulting in an accelerated dehydrogenation kinetics on u‐NiV‐LDH. The synergy of the proton detachment from the laminate and the methanol dehydrogenation oxidation contributes to the excellent MOR performance of u‐NiV‐LDH.