Sub-2 nm platinum nanocluster decorated on yttrium hydroxide as highly active and robust self-supported...

Downsizing Pt particles and incorporating water dissociation site represents a promising strategy for maximizing atomic utilization efficiency and enhancing catalytic performance in Pt-based hydrogen evolution reaction (HER) electrocatalysts. Here, we present a self-supported Pt/Y(OH)₃ electrocatalyst through a synergistic combination of anion insertion-enhanced electrodeposition and chemical deposition at ambient temperature. The resultant architecture features sub-2 nm Pt nanoclusters (with an average diameter of 1.3 nm) decorated on Y(OH)₃. The optimized Pt₂₄/Y(OH)₃ electrode exhibits impressive HER catalytic performance with an overpotential of 31 mV at 10 mA cm^-2, and maintains stability for 250 h under a high current density of 500 mA cm^-2, surpassing the benchmark Pt/C electrocatalyst. Experimental results and density functional theory (DFT) calculations demonstrate that the sub-2 nm scale of Pt enrich the active sites and the coupled Y(OH)₃ act as a water-dissociation promotor favoring the generation of adsorbed hydrogen on Pt site, thereby boosting the HER activity. Additionally, the strong interaction between Pt nanocluster and Y(OH)₃ stabilizes platinum species from agglomeration, while the robust adhesion of the electrocatalyst to the graphite substrate enhances electron transportation and contributes to superior stability of the catalyst. These results suggest that the innovative self-supported Pt/Y(OH)₃ electrode holds significant promise for practical applications in alkaline hydrogen evolution.