Pt Single-Atom collaborate with Pt Atom-Clusters by an In-Situ confined strategy for accelerating electrocatalytic hydrogen evolution

Heterogeneous catalysts with atomic dispersion play an important role in electrocatalysis. In addition to the single-atom, modifying the intrinsic catalytic capacity of single-atom catalysts through cooperative atom-clusters is an effective way to increase active sites and improve mass activity. Herein, a composite electrocatalytic material (PtM@CN) with partial Pt single-atoms and partial Pt atom-clusters was obtained by pyrolysis of the thermostable UiO-66-PtTCPP precursor. Remarkably, beneficial to the synergistic effect of Pt single-atom and Pt atom-clusters as well as the strong metal-support interaction, the PtM@CN catalyst showed excellent hydrogen evolution reaction (HER) activity and stability in both acidic and alkaline electrolytes. Moreover, X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations shows that the existence of Pt single-atom and Pt atom-clusters could rationally adjust electronic structure of supported metals and impact adsorption energy of reaction intermediates, which play an essential role in enhancing the electrocatalytic activity of HER.