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• Highly porous Mo 2 C/C is prepared using the N, K co-activated biochar as carbon source and matrix. • The obtained porous Mo 2 C/C shows a large specific surface area with nitrogen doping. • The porous architecture with a large specific surface area can afford abundant catalytic sites. • The interconnected N-rich carbon matrix provides efficient electron transfer pathways for HER. Molybdenum carbide (Mo 2 C) has offered great promise to serve as a platinum substitute towards efficient hydrogen evolution reaction (HER). However, both the lack of exposed catalytic sites and strong Mo–H binding strength will strongly hinder the HER process for Mo 2 C-based electrocatalysts. Herein, a scalable strategy is proposed for the preparation of highly porous Mo 2 C/C electrocatalysts with a specific surface area up to 611 m2 g−1 as well as uniform nitrogen doping derived from N, K co-activated biochar (NKAB). And the porous architecture with a large specific surface area can afford abundant catalytic sites. Additionally, both the Mo 2 C and carbon matrix are doped with nitrogen effectively, which can optimize the hydrogen adsorption free energy of Mo 2 C/C electrocatalysts associated with a higher intrinsic activity. As a result, the active site density and intrinsic activity of Mo 2 C/NKAB have been promoted simultaneously on account of the high specific surface area and nitrogen doping. Furthermore, the interconnected N-rich carbon matrix provides efficient electron transfer pathways for superior HER kinetics. Ultimately, the overall HER performances of Mo 2 C/NKAB can be significantly enhanced. [ABSTRACT FROM AUTHOR]