Lattice Mismatched Platinum-Tellurium@Platinum-Ruthenium Core@Shell Nanorods Achieve Ultrahigh Alkaline Hydrogen Electrocatalysis for Dual Practical Devices.

Abstract

Lattice mismatch engineering is necessary yet challenging for core@shell structured platinum (Pt)-based catalysts in alkaline hydrogen electrocatalysis. Herein, a series of lattice mismatched Pt-tellurium@Pt-ruthenium core@shell nanorods (LM-PtTe₂@Pt_xRu NRs, x = 2, 4, 9, 12, 16) are constructed for alkaline hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER). The optimized LM-PtTe₂@Pt₉Ru/C exhibits much better HOR and HER performances versus commercial PtRu/C and Pt/C. More importantly, its ultrahigh membrane electrode assembly (MEA) power densities of 26.4/21.0 W mg_Pt+Ru ^-1 in H₂-O₂/H₂-air media for anion exchange membrane fuel cell (AEMFC) and remarkable MEA performance of 1.55 V@0.5 A cm^-2/2.0 V@5.8 A cm^-2 for AEM water electrolysis (AEMWE) outperform the vast majority of PtRu-based catalysts reported to date, displaying an unprecedented potential in dual practical devices. The lattice mismatch degree of 18.7% between trigonal PtTe₂ and cubic Pt₉Ru induces numerous lattice dislocations and unusual lattice strain effect in LM-PtTe₂@Pt₉Ru/C, which simultaneously optimizes the surface electron distribution and the adsorption of intermediates, responsible for its high hydrogen catalysis performance. This work aims to achieve the high-performance MEA catalysis for AEMFC and AEMWE with lattice mismatch engineering induced by these well-organized PtRu-based core@shell nanocatalysts.