Single-atom Pt promoted Mo2C for electrochemical hydrogen evolution reaction

Abstract Hydrogen generation from electrochemical water splitting powered by renewable energy is important to the sustainable society, but the prohibitive cost of current Pt electrocatalyst has impeded the large-scale production of hydrogen by water electrolysis. In this contribution, a new low-Pt electrocatalyst for hydrogen evolution reaction (HER) has been fabricated by a facile one-pot synthesis approach, in which Pt2+ cations and phosphomolybdic acid confined in the metal-organic frameworks (MOFs) were submitted to pyrolysis to yield Pt single atoms dispersed into Mo2C nanocrystals in 3D porous carbon matrix. The as-synthesized Pt1-Mo2C-C catalyst with Pt content of only 0.7 wt% exhibited remarkably enhanced activity for HER in 1 M KOH, with overpotential at 10 mA/cm2 lowered from 211 mV to 155 mV and 7-fold higher mass activity (7.14 A/mgPt) than the benchmark 20 wt% Pt/C. The promoted activity can be attributed to the electronic interaction between Pt single atoms and Mo2C surface, which not only improved water activation but also strengthened hydrogen adsorption, as indicated by FTIR and microcalorimetric characterizations.