Pt-O bond as an active site superior to Pt 0 in hydrogen evolution reaction

The oxidized platinum (Pt) can exhibit better electrocatalytic activity than metallic Pt0 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 Na5[H3Pt(IV)W6O24] (PtW6O24) and Na3K5[Pt(II)2(W5O18)2] (Pt2(W5O18)2) as the platinum oxide model to investigate the HER performance. Electrocatalytic experiments show the mass activities of PtW6O24/C and Pt2(W5O18)2/C are 20.175 A mg−1 and 10.976 A mg−1 at 77 mV, respectively, which are better than that of commercial 20% Pt/C (0.398 A mg−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 H2. 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 H2 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 H2 evolution electrocatalysis.