Molten‐Salt Electrochemical Deoxidation Synthesis of Platinum‐Neodymium Nanoalloy Catalysts for Oxygen Reduction Reaction
Chenming Fan, Guomin Li, Jingjiu Gu, Qiang Wang, Shenggang Li, Bing Li
Abstract
Abstract Platinum‐rare earth metal (Pt‐RE) nanoalloys are regarded as a potential high performance oxygen reduction reaction (ORR) catalyst. However, wet chemical synthesis of the nanoalloys is a crucial challenge because of the extremely high oxygen affinity of RE elements and the significantly different standard reduction potentials between Pt and RE. Here, this paper presents a molten‐salt electrochemical synthetic strategy for the compositional‐controlled preparation of platinum‐neodymium (Pt‐Nd) nanoalloy catalysts. Carbon‐supported platinum‐neodymium (Pt x Nd/C) nanoalloys, with distinct compositions of Pt 5 Nd and Pt 2 Nd, are obtained through molten‐salt electrochemical deoxidation of platinum and neodymium oxide (Pt‐Nd 2 O 3 ) precursors supported on carbon. The Pt x Nd/C nanoalloys, especially the Pt 5 Nd/C exhibit a mass activity of 0.40 A mg −1 Pt and a specific activity of 1.41 mA cm −2 Pt at 0.9 V versus RHE, which are 3.1 and 7.1 times higher, respectively, than that of commercial Pt/C catalyst. More significantly, the Pt 5 Nd/C catalyst is remarkably stable after undergoing 20 000 accelerated durability cycles. Furthermore, the density‐functional‐theory (DFT) calculations confirm that the ORR catalytic performance of Pt x Nd/C nanoalloys is enhanced by compressive strain effect of Pt overlayer, causing a suitable weakened binding energies of O * and .