Pt-O bond as an active site superior to Pt0 in hydrogen evolution reaction

The oxidized platinum (Pt) can exhibit better electrocatalytic activity than metallic Pt-0 in the hydrogen evolution reaction (HER), which has aroused great interest in exploring the role of oxygen in Pt-based catalysts. Herein, we select two structurally well-defined polyoxometalates Na-5[(H3PtW6O24)-W-(IV)] (PtW6O24) and Na3K5[Pt-2((II))(W5O18)(2)] (Pt-2(W5O18)(2)) as the platinum oxide model to investigate the HER performance. Electrocatalytic experiments show the mass activities of PtW6O24/C and Pt-2(W5O18)(2)/C are 20.175Amg(-1) and 10.976Amg(-1) at 77mV, respectively, which are better than that of commercial 20% Pt/C (0.398Amg(-1)). The in situ synchrotron radiation experiments and DFT calculations suggest that the elongated Pt-O bond acts as the active site during the HER process, which can accelerate the coupling of proton and electron and the rapid release of H-2. This work complements the knowledge boundary of Pt-based electrocatalytic HER, and suggests another way to update the state-of-the-art electrocatalyst. While converting water to H-2 with a catalyst offers a renewable means to produce carbon-neutral fuels, understanding the catalytic active sites has proven challenging. Here, authors show a structurally well-defined model complex with Pt-O bonding to enable efficient H-2 evolution electrocatalysis.