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‐PtTe 2 @Pt x Ru NRs, x = 2, 4, 9, 12, 16) are constructed for alkaline hydrogen oxidation reaction (HOR) and hydrogen evolution reaction (HER). The optimized LM‐PtTe 2 @Pt 9 Ru/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 H 2 ‐O 2 /H 2 ‐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 PtTe 2 and cubic Pt 9 Ru induces numerous lattice dislocations and unusual lattice strain effect in LM‐PtTe 2 @Pt 9 Ru/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.