Ultrathin Nanosheet of Graphdiyne-Supported Palladium Atom Catalyst for Efficient Hydrogen Production.

Atomic catalysts are promising alternatives to bulk catalysts for the hydrogen evolution reaction (HER), because of their high atomic efficiencies, catalytic activities, and selectivities. Here, we report the ultrathin nanosheet of graphdiyne (GDY)-supported zero-valent palladium atoms and its direct application as a three-dimensional flexible hydrogen-evolving cathode. Our theoretical and experimental findings verified the successful anchoring of Pd to GDY and the excellent catalytic performance of Pd/GDY. At a very low mass loading (0.2%: 1/100 of the 20 wt % Pt/C), Pd/GDY required only 55 mV to reach 10 mA cm (smaller than 20 wt % Pt/C); it showed larger mass activity (61.5 A mg) and turnover frequency (16.7 s) than 20 wt % Pt/C and long-term stability during 72 hr of continuous electrolysis. The unusual electrocatalytic properties of Pd/GDY originate from its unique and precise structure and valence state, resulting in reliable performance as an HER catalyst.