Metal–support interactions (MSIs) is essential for the understanding of structure–performance relationship and designing in heterogeneous catalysis area. This review mainly summarizes the current theoretical and experimental research of MSIs.

Electrocatalytic nitrogen fixation at room temperature and ambient pressure is considered to be one of the most energy-efficient and environmentally-friendly approaches to ammonia (NH₃) production. The construction of efficient catalysts for the electrocatalytic nitrogen reduction reaction (NRR) remains a significant challenge. However, there have been no reports dedicated to non-noble bimetals on nitrogen-doped carbons as efficient NRR electrocatalysts, considered from either side of the theoretical volcano plot for the NRR. Herein, Mo–Co bimetallic nanoparticles anchored on nitrogen-doped porous carbon (Mo–Co/NC) are developed for the first time and serve as a cost-effective catalyst candidate for the NRR. In comparison to single-metallic Co/NC, a bimetallic Mo–Co/NC catalyst exhibits the enhanced activity and selectivity of NRR electrocatalysis with an ammonia yield of 89.8 μmol h⁻¹ g_cat. ⁻¹ and a faradaic efficiency of 13.5%, at a low operating potential of −0.10 V (vs. RHE) in 0.1 M Na₂SO₄. Moreover, the composite catalyst shows high electrochemical stability and selectivity during 50 000 s of NRR processing. The favorable NRR electrocatalytic activity of Mo–Co/NC could be ascribed to the synergistic effect of strongly adsorbed Mo and weakly adsorbed Co composite. This work provides a facile strategy towards the design of porous non-precious metallic electrocatalysts for efficient NRR under ambient conditions.

Here, we demonstrate for the first time the activity trend of ZnO > CuO > NiO > CoO for 2e ⁻ ORR electrocatalysis with the selectivity of 90.0%, 82.8%, 79.4%, and 36.8%, respectively.