Platinum (Pt) is the most active and stable HER catalyst, but its high cost and low abundance hinder its widespread applications. [3][4][5][6] Recently, tremendous efforts have been devoted to the search for noble-metal-free catalysts to replace Pt-based catalysts in the generation of H 2 with a high current density at a low overpotential. [7][8][9][10] In particularly, molybdenum carbides and molybdenum phosphides have been demonstrated as active and robust HER catalysts due to their high conductivities, high catalytic activities, and excellent stabilities. [11][12][13][14][15] The high-performance catalytic activities of these materials may be related to the function of their heteroatoms, such as phosphorus, which possesses lone-pair electrons in 3p orbitals and vacant 3d orbitals and can thus accommodate the surface charge as well as induce local charge density. [16] Nitrides of transition metals have also been shown to have excellent catalytic activities in the HER. [17][18][19][20][21] Taking all the above works together, we predicted that nitrogen (N)-doped molybdenum carbide and phosphide hybrids, N@MoPCx, might be promising electrocatalysts for efficient hydrogen evolution. However, it remains a challenge to obtain a targeted N-doped molybdenum carbide and phosphide hybrid with a uniform distribution and desirable porosity that also exhibits high electrocatalytic activity, which requires (i) preventing the aggregation of nanoparticles; (ii) obtaining a desirable porosity; and (iii) achieving uniform carburization, phosphorization, and heteroatoms doping. To avoid the aggregation of nanoparticles and increase their electrical conductivities, substrates such as carbon cloth, carbon nanotubes, and graphene have been introduced into metal-based catalysts for use in multiple catalytic reactions. [22][23][24] However, the introduction of substrates creates additional cost and still cannot completely prevent aggregation.Polyoxometalates (POMs) are a special class of well-defined molecular metal oxide clusters with a wide range of applications in medicine, catalysis, materials sciences, etc. [25][26][27][28][29][30] It is well known that organoimido derivatives of POMs can be prepared by introducing exogenous N-containing ligands to replace the oxo groups in the POM clusters. [31][32][33][34][35] The controllable preparation of multifunctionalized derivatives of hexamolybdate has been achieved by the powerful N,N′-dicyclohexylcarbodiimide (DCC)-dehydrating protocol by Ruhlmann and our group. [36,37] P-containing organoimido derivatives of POMs could be The efficient evolution of hydrogen through electrocatalysis is considered a promising approach to the production of clean hydrogen fuel. Platinum (Pt)-based materials are regarded as the most active hydrogen evolution reaction (HER) catalysts. However, the low abundance and high cost of Pt hinders the large-scale application of these catalysts. Active, inexpensive, and earth-abundant electrocatalysts to replace Pt-based materials would be highly beneficial to the ...