Mo-modified Pt/C electrocatalyst prepared by the catalytic decomposition of molybdenum peroxo-complexes for the hydrogen oxidation reaction with enhanced CO tolerance

• Published in: Electrochimica acta 2024-12, Vol.508, p.145208, Article 145208
• Main Authors: Simonov, Pavel A., Volostnikov, Eldar A., Gerasimov, Evgenii Yu, Pakharukova, Vera P., Kvon, Ren I., Kozlov, Denis V., Kuznetsov, Aleksey N.
• Format: Article
• Language: English
• Subjects: CO tolerance; Hydrogen oxidation reaction (HOR); Molybdenum peroxo complex; Platinum molybdenum catalyst
• ISSN: 0013-4686
• DOI: 10.1016/j.electacta.2024.145208

•The PtMo/C electrocatalyst was prepared by the new method via the catalytic decomposition of molybdenum peroxo-complexes on commercial Pt/C catalyst.•The treatment of Pt2Mo1/C precursor in H2 flow at 600 °C led to forming PtMo alloy contained 15 % of all molybdenum, and the rest amount of Mo covered Pt particles surface in the form of MoO3 clusters.•Mo-modified Pt/C electrocatalyst with a molar ratio of Pt:Mo = 2:1 demonstrates 100 times higher CO tolerance in comparison with the pristine commercial 20 % Pt/C catalyst. Commercial 20 % Pt/C catalyst was modified by molybdenum via catalytic decomposition of peroxocomplexes of molybdenum with the subsequent reduction of the Pt2Mo1/C precursor in H2 flow at 600 °C. The detailed HRTEM, EDX, XRD and XPS studies showed that amorphous molybdenum oxide was deposited on Pt particles surface and partially on carbon support. After reduction of the Pt2Mo1/C precursor, the substantial Mo fraction merges the structure of Pt particles thus forming PtMo alloy with reduced lattice parameter, while the rest of molybdenum covers the surface of PtMo particles as MoO3. The presented method of Mo-modification of Pt-based catalysts provides rather simple way to vary Pt:Mo molar ratio. Electrochemical study revealed that the amount of the surface MoO3 plays a key role in the CO tolerance of the PtMo/C catalyst. As prepared Pt2Mo1/C precursor is 15 times superior to the Pt/C catalyst in the CO-tolerance. After reduction, the Pt2Mo1/C electrocatalyst exhibits extremely high CO-tolerance, more than 100 times higher than that of the pristine commercial platinum catalyst.