A DFT study of oxygen reduction reaction mechanism over O-doped graphene-supported Pt4, Pt3Fe and Pt3V alloy catalysts. (27th April 2015)

• Record Type: Journal Article
• Authors: Jin, Nian; Han, Jinyu; Wang, Hua; Zhu, Xinli; Ge, Qingfeng
• Is Part Of: International journal of hydrogen energy. Volume 40:Number 15(2015)
• Page Start: 5126
• Page End: 5134
• Publication Date: 2015-04-27
• Subjects: O-doped graphene -- Supported catalyst -- Bimetallic -- ORR reactivity; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2015.02.101
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Density functional theory calculations were performed to investigate the pathways of the oxygen reduction reaction over the Pt4 and Pt3 M (M = Fe, V) clusters supported on the O-doped graphene substrate. The results show that the defect sites resulting from oxygen doping become the anchor sites for metal clusters. Our results also showed that O2 adsorbs as a di-oxygen species on the supported Pt4 and Pt3 Fe clusters, but dissociates spontaneously on supported Pt3 V. The di-oxygen species dissociates into co-adsorbed HO* and O* upon reduction on both supported Pt4 and Pt3 Fe and no stable HOO* intermediates were isolated. On supported Pt4, further reduction via both HO* + HO* and H2 O* + O* routes is possible, with reaction favoring the HO* + HO* route energetically. On supported Pt3 Fe, the HO* + HO* and H2 O* + O* routes are competitive. On supported Pt3 V, the reduction reaction is likely to proceed exclusively through the HO* + HO* route as no stable co-adsorbed H2 O and O* state was isolated. The results were discussed in the context of the experimentally observed enhancement of ORR reactivity on the graphene supported Pt3 Cr and Pt3 Co nanocatalysts. Graphical abstract: Highlights: Oxygen doping site in graphene forms an anchor for supported metal clusters. O2 adsorbs as a di-oxygen species on supported Pt4 and Pt3 Fe clusters. O2 dissociates spontaneously on supported Pt3 V. On supported Pt4 and Pt3 Fe, both HO* + HO* and H2 O* + O* routes are possible. On supported Pt3 V, the HO* + HO* route dominates.