Electronic regulation of Mo₂C and thus intrinsically improved HER activity via balanced Volmer and Heyrovsky/Tafel steps.

The hydrogen evolution reaction using noble-metal free electrocatalysts has captured increasing attention due to its importance in renewable hydrogen production. Herein, a highly active and stable electrocatalyst of MoC encapsulated by graphitized carbon shells (nanoMoC@GS) has been developed via an in situ carburization of a Mo-based metal–organic framework (Mo-MOF) with the atomic periodic structure. The ultrafine MoC nanoparticles (∼3 nm) confined by 1–3 layered graphite shells significantly favor the efficient HER in both acidic and basic media. In particular, a low overpotential (η₁₀ = 124 and 77 mV at a current density of −10 mA cm⁻²), a small Tafel slope (43 and 50 mV dec⁻¹) and a high exchange current density (j₀ = 0.015 and 0.212 mA cm⁻²) are achieved on nanoMoC@GS in 0.5 M H₂SO₄ and 1.0 M KOH, respectively. Such remarkable activity, outperforming most current noble-metal-free electrocatalysts, stems from the cooperative/synergistic effects of ultrafine MoC nanostructure, ultrathin and conductive graphitized carbon shells, and enriched porosity. This work demonstrates a feasible way to design high-performance electrocatalysts via converting “atomic contact” hybrid structures (e.g., MOFs), illustrating a new perspective for developing nanocatalysts in the energy chemistry field.

A highly stable MTP catalyst, boron-modified hierarchical nanocrystalline ZSM-5 zeolite, has been synthesized by a facile salt-aided seed-induced route. It exhibits a long lifetime (about 725 h) even at a high WHSV (4.0 h⁻¹).