D-Orbital Manipulated Ru Nanoclusters for High-Efficiency Overall Water Splitting at Industrial-Level Current Densities

Owing to the Pt-like electrocatalytic capability and moderate price, Ru-based catalysts are considered as the Pt alternatives for electrochemical water splitting. However, they demonstrate limited catalytic performance under industrial-level current densities. Herein, a novel electrocatalyst with an extremely low amount (0.85 wt.%) of Ru nanoclusters anchored on Cr-doped Fe-metal-organic frameworks (Ru@CrFeMOF) through a robust CrORu bond is presented. The study unveils that such an architecture facilitates fast electron transfer and manipulates the highest occupied d orbital and d-band centers of Ru sites, favoring both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) catalysis. The as-prepared catalyst performs excellent reaction activity of 21 mV@10 mA cm-2 for HER and 230 mV@50 mA cm-2 for OER in alkaline solution, and realizes excellent water-splitting performance at industrial-level current densities (1.72 V@1000 mA cm-2), surpassing the state-of-the-art literatures. The CrORu bond creates a strong interaction between the Ru nanocluster and Cr-doped Fe-MOF, which regulates the orbital electronic structure of Ru, optimizing the adsorption energy of reaction intermediates and then improving both hydrogen and oxygen evolution reaction performance.image