Interfacial lattice strain and electronic transfer induced by lignin-derived carbon coupled with Ni-Mn2Mo3O8 heterojunction for improving industrial-level urea electrolysis

Although nickel-based catalysts exhibit certain urea electrolysis performance, their application is hindered by the sluggish indirect or direct urea oxidation reaction (UOR) and either the Volmer-Tafel or Heyrovsky mechanism of hydrogen evolution reaction (HER). Herein, we propose utilizing interfacial lattice strain and electronic transfer induced by lignin-derived carbon coupled with Ni-Mn 2 Mo 3 O 8 heterojunction (denoted as Ni-Mn 2 Mo 3 O 8 @C) to increase the lattice imperfection and adjust electronic structure, enhancing its urea electrolysis activity. Ni-Mn 2 Mo 3 O 8 @C exhibits low potentials for UOR ( E 10/1000/2000mA = 1.21/1.33/1.41   V) and HER ( E -10/-1000/-2000mA = -52.57/-329.41/-362.46   mV), which undergoes fast direct oxidation reaction for UOR and Volmer-Heyrovsky steps for HER. Meanwhile, Ni-Mn 2 Mo 3 O 8 @C operates stably at 1000   mA   cm −2 for 140   hours in membrane electrode assembly, due to the corrosion resistance of lignin-derived carbon and superhydrophilicity of self-supported porous structure. This work proposes a promising catalyst for HER/UOR and demonstrates a feasible route to designing nickel-based catalysts in practical applications of urea electrolysis.