TiCT MXenes and MnO nanoparticles synergistically promote the electrochemical synthesis of ammonia under ambient conditions.

Ammonia serves as a hydrogen energy carrier and a renewable, zero-carbon fuel alternative that is safely transportable. The electrochemical catalytic reduction of N to NH in aqueous electrolytes at ambient temperature and pressure (eNRR) using electricity generated from renewable energy sources such as solar and wind power can provide an environmentally friendly approach. To effectively suppress the occurrence of hydrogen evolution side reactions, it is necessary to design and synthesize catalysts with high selectivity for N adsorption. Owing to the ability of transition metals with unoccupied d orbitals to significantly promote the adsorption of N molecules and the activation of inert bonds, researchers have explored manganese-oxide catalysts through both experimental and theoretical studies. However, manganese oxides are semiconductor materials with poor conductivity. To solve this problem, the TiCT MXene material can be introduced as a carrier for manganese oxide particles. In this study, the TiC@MnO composite was used as an electrocatalyst for ammonia synthesis under ambient conditions using a simple method. Benefiting from the synergistic catalytic effect of MXene and MnO, the composite exhibits excellent catalytic performance for ammonia synthesis, with an NH yield rate of 53.7 μg h mg and satisfactory FE of 10.4% at -0.6 V ( RHE) under ambient conditions. The composite catalyst exhibits excellent stability, durability, and selectivity, with outstanding synergistic effects, surpassing most reported NRR electrocatalysts. This simple and versatile strategy may offer researchers inspiration for rationally designing highly efficient NRR electrocatalysts.