Role of Oxidized Mo Species on the Active Surface of Ni–Mo Electrocatalysts for Hydrogen Evolution under Alkaline Conditions

Jeremy Bau, Sergey Kozlov, Luis Azofra Mesa, Samy Ould-Chikh, Abdul-Hamid M. Emwas, Hicham Idriss, Luigi Cavallo, Kazuhiro Takanabe

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

A Ni–Mo composite functions as a promising non-noble metal electrocatalyst for the hydrogen evolution reaction (HER) in alkaline water. Despite its industrial relevance, the kinetic origin of the high catalytic activity remains under debate. The present report discusses a reaction mechanism of HER on Ni–Mo catalysts by combining experimental and theoretical studies. In contrast to a Ni catalyst, a Ni–Mo catalyst is insensitive to CO gas introduced during HER. In situ spectroscopic measurements including Raman spectroscopy and electron paramagnetic resonance (EPR) show that Mo3+ prevails during HER catalysis. Density functional theory (DFT) simulations corroborate the thermodynamic stability and HER activity of Mo3+-containing centers on Ni(111) at HER potentials. Notably, Ni is demonstrated to play no direct role as a catalytic site but to effectively disperse and activate the oxidized catalytic Mo species. The results illustrate how to improve the electrocatalytic activity for alkaline HER.
Original languageEnglish (US)
Pages (from-to)12858-12866
Number of pages9
JournalACS Catalysis
DOIs
StatePublished - Oct 20 2020

Fingerprint Dive into the research topics of 'Role of Oxidized Mo Species on the Active Surface of Ni–Mo Electrocatalysts for Hydrogen Evolution under Alkaline Conditions'. Together they form a unique fingerprint.

Cite this