Al13@Pt42 core-shell cluster for oxygen reduction reaction.

ABSTRACT: To increase Pt utilization for oxygen reduction reaction (ORR) in fuel cells, reducing particle sizes of Pt is a valid way. However, poisoning or surface oxidation limits the smallest size of Pt particles at 2.6?nm with a low utility of 20%. Here, using density functional theory calculations, we develop a core-shell Al13@Pt42 cluster as a catalyst for ORR. Benefit from alloying with Al in this cluster, the covalent Pt-Al bonding effectively activates the Pt atoms at the edge sites, enabling its high utility up to 70%. Valuably, the adsorption energy of O is located at the optimal range with 0.0-0.4?eV weaker than Pt(111), while OH-poisoning does not observed. Moreover, ORR comes from O2 dissociation mechanism where the rate-limiting step is located at OH formation from O and H with a barrier of 0.59?eV, comparable with 0.50?eV of OH formation from O and H2O on Pt(111).

SUBMITTER: Xiao BB 

PROVIDER: S-EPMC5381497 | biostudies-literature | 2014 Jun

REPOSITORIES: biostudies-literature