General approach for atomically dispersed precious metal catalysts toward hydrogen reaction

As a carbon-free energy carrier, hydrogen has become the pivot for future clean energy, while efficient hydrogen production and combustion still require precious metal-based catalysts. Single-atom catalysts (SACs) with high atomic utilization open up a desirable perspective for the scale applications of precious metals, but the general and facile preparation of various precious metal-based SACs remains challenging. Herein, a general movable printing method has been developed to synthesize various precious metal-based SACs, such as Pd, Pt, Rh, Ir, and Ru, and the features of highly dispersed single atoms with nitrogen coordination have been identified by comprehensive characterizations. More importantly, the synthesized Pt- and Ru-based SACs exhibit much higher activities than their corresponding nanoparticle counterparts for hydrogen oxidation reaction and hydrogen evolution reaction (HER). In addition, the Pd-based SAC delivers an excellent activity for photocatalytic hydrogen evolution. Especially for the superior mass activity of Ru-based SACs toward HER, density functional theory calculations confirmed that the adsorption of the hydrogen atom has a significant effect on the spin state and electronic structure of the catalysts.