TY - JOUR

T1 - Bimetallic NiM/C (M = Cu and Mo) Catalysts for the Hydrogen Oxidation Reaction: Deciphering the Role of Unintentional Surface Oxides in the Activity Enhancement

AU - Oshchepkov, Alexandr G.

AU - Simonov, Pavel A.

AU - Kuznetsov, Aleksey N.

AU - Shermukhamedov, Shokir A.

AU - Nazmutdinov, Renat R.

AU - Kvon, Ren I.

AU - Zaikovskii, Vladimir I.

AU - Kardash, Tatyana Yu

AU - Fedorova, Elizaveta A.

AU - Cherstiouk, Olga V.

AU - Bonnefont, Antoine

AU - Savinova, Elena R.

N1 - The authors acknowledge CKP VTAN NSU for the usage their experimental equipment. R.R.N. and S.A.S. also thank the RFBR (project No 20-03-00772). Publisher Copyright: © 2022 American Chemical Society.

PY - 2022/12/16

Y1 - 2022/12/16

N2 - Emerging interest in the platinum group metal (PGM)-free electrocatalysts calls for a fundamental understanding of the key factors determining their activity, the latter being critical for the development of efficient catalysts. Ni-based materials show high promises as PGM-free anodes of anion exchange membrane fuel cells (AEMFCs). However, their hydrogen oxidation reaction (HOR) activity can differ by several orders of magnitude, and the factors responsible for this are still being debated. In this work, the effect of unintentional surface oxides in Ni/C and NiM/C (M = Cu and Mo) is revealed by benchmarking either the catalysts conventionally stored under ambient conditions or purposely reduced "oxide-free"materials. The analysis of electrocatalytic data complemented by detailed material characterization, Monte Carlo simulations, and density functional calculations, underlines the key importance of surface oxides in the HOR catalysis on Ni, NiCu, and NiMo electrodes. These findings underscore the need to measure the HOR activity of Ni-based catalysts in the absence of surface oxides in order to unambiguously interpret the influence of other factors (such as the electronic effect of the second element) on activity enhancement.

AB - Emerging interest in the platinum group metal (PGM)-free electrocatalysts calls for a fundamental understanding of the key factors determining their activity, the latter being critical for the development of efficient catalysts. Ni-based materials show high promises as PGM-free anodes of anion exchange membrane fuel cells (AEMFCs). However, their hydrogen oxidation reaction (HOR) activity can differ by several orders of magnitude, and the factors responsible for this are still being debated. In this work, the effect of unintentional surface oxides in Ni/C and NiM/C (M = Cu and Mo) is revealed by benchmarking either the catalysts conventionally stored under ambient conditions or purposely reduced "oxide-free"materials. The analysis of electrocatalytic data complemented by detailed material characterization, Monte Carlo simulations, and density functional calculations, underlines the key importance of surface oxides in the HOR catalysis on Ni, NiCu, and NiMo electrodes. These findings underscore the need to measure the HOR activity of Ni-based catalysts in the absence of surface oxides in order to unambiguously interpret the influence of other factors (such as the electronic effect of the second element) on activity enhancement.

KW - copper

KW - density functional theory

KW - hydrogen oxidation reaction (HOR)

KW - in situ reduction

KW - molybdenum

KW - Monte Carlo simulations

KW - nickel

KW - nickel oxide

UR - http://www.scopus.com/inward/record.url?scp=85143412148&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/94b114eb-2171-3787-a2ae-e4ef9098b2b2/

U2 - 10.1021/acscatal.2c03720

DO - 10.1021/acscatal.2c03720

M3 - Article

AN - SCOPUS:85143412148

VL - 12

SP - 15341

EP - 15351

JO - ACS Catalysis

JF - ACS Catalysis

SN - 2155-5435

IS - 24

ER -