Wei Ding, Meirong Xia, Zidong Wei, Siguo Chen, Jin-Song Hu, Li-jun Wan, Xueqiang Qi, Xiaohua Hu and Li Li

Chem. Commun., 2014,50, 6660-6663

http://pubs.rsc.org/en/content/articlelanding/2014/cc/c4cc02180k#!divAbstract

Abstract (click image for pdf file)

Palladium has been the focus of recent research on alternative Pt catalysts for the oxygen reduction reaction (ORR). We show that the activity and stability of Pd toward the ORR can be enhanced by Pd–O-oxides covalent bonding when Pd is supported on exfoliated montmorillonite (ex-MMT) nanoplatelets. It was experimentally observed that a thin PdOx layer with a Pd–O–MMT junction is formed at the particle/support interface. First-principle calculations further revealed that the junction is formed between the Pd atoms and the O atoms in the AlO6 octahedra of the ex-MMT. Because of the influence of the ex-MMT on the electronic structure of Pd, the electronic structure of Pd on ex-MMT is similar to that of Pt and the bonding strength of Oads is diminished. This diminished bond strength allows for the ORR on the Pd/ex-MMT to proceed through an efficient pathway, as is the case with Pt. This study opens a new pathway to modify of the electronic structure of Pd for enhanced ORR activity and stability.