In-situ Pt reduction induced topological transformation of NiFe-MOF for industrial seawater splitting

Metal-support interaction (MSI) is regarded as an indispensable manner to stabilize active metals and modulate catalytic activity, which shows great potentials in developing of efficient hydrogen evolution reaction (HER) electrode with high activity and strong robustness. Herein, this work presents a novel heterostructure with ultrafine platinum quantum dots (Pt QDs) on defective catalytic supports derived from metal-organic frameworks (MOFs). It is indicated substantial oxygen vacancies can be generated and Pt–Pt bonds can be optimized through topological transformation. The resulting Pt/T-NiFe-BDC (BDC: C 8 H 6 O 4 ) exhibits competitive HER activity in alkaline seawater, attaining ultralow overpotentials of 158 and 266 mV at 500 and 1000 mA cm –2 with fast kinetics and outstanding stability. An asymmetric water electrolyzer using Pt/T-NiFe-BDC as a cathode only requires a voltage of 1.89 V to generate an industrial density of 1000 mA cm –2 and shows no attenuation in 500-h continuous test at 500 mA cm –2 . Theoretical calculations and in-situ spectroscopic analysis reveal the reversible hydrogen spillover mechanism, in which oxygen vacancies facilitate the sluggish water dissociation and Pt QDs promote the H* combination. This study provides a new paradigm to engineer metal-supported catalysts for efficient and robust seawater splitting.