C15‐Phase Platinum‐Lanthanide Intermetallics for Efficient Hydrogen Evolution: Identifying Lanthanide's Enhanced Mechanism
Wei Yan, Yimin Mou, Meng Li, Kaiyue Ma, Zhiwen Xu, Tingyu Lu, Han Du, Caikang Wang, Huamei Sun, L.F. Chen, Yawen Tang, Yu Wang, Gengtao Fu
Abstract
Abstract Platinum‐Lanthanide (Pt‐Ln) intermetallic compounds (IMCs) are a promising new class of electrocatalytic materials, yet their synthesis remains a significant challenge, and the role of ordered Ln sites in enhancing catalytic performance is not fully understood. Herein, an effective and rapid avenue for synthesizing carbon‐supported C15‐phase Pt 2 Ln IMCs (Ln: Sm, Eu, Gd, and Tb) through Joule heating technology is proposed. The JH‐Pt 2 Ln/C IMCs exhibit excellent electrocatalytic performance toward alkaline hydrogen evolution reaction (HER), in which JH‐Pt 2 Tb/C presents the lowest overpotential of 17 mV at 10 mA cm −2 . The ordered Pt 2 Tb structure offers favorable Pt 2 dimer sites for the desorption of H* intermediates, in contrast to the Pt 3 trimer sites in disordered Pt 2 Tb and pure Pt. The ordered Tb sites play a bifunctional role in HER: i) The oxophilic Tb atoms are in favor of the H 2 O adsorption and dissociation through Tb‐4f‐OH binding; ii) The strong Tb 4f‐Pt 5d orbital hybridization leads to form negatively charged Pt sites, which promotes the desorption of H* intermediates. Furthermore, the anion exchange membrane water electrolyzer equipped with JH‐Pt 2 Tb/C delivers a low voltage of only 1.79 V cell to reach 1 A cm −2 and maintains the stable operation at 1 A cm −2 for over 100 h.