Carbon dioxide reduction to produce various fuels and chemical products can simultaneously fix carbon dioxide and convert renewable electrical energy into chemical energy storage, making it an attractive route to achieve a closed-loop carbon cycle. This talk will mainly cover our research in the past 5 years in developing efficient catalysts and their interfaces for CO₂ reduction reaction. I will then focus on metal complexes, an important class of catalysts with the advantages of well-defined and controllable structures. Due to the molecular aggregation and leaching effects in the catalytic process, the low conversion frequency, low electron transport rate and poor stability of molecular catalysts in the heterogeneous catalytic process are encountered. I will summarize our group’ s recent progress in understanding the influence of catalyst interface aggregation effect on catalytic mechanism and product selectivity; this includes the in-depth understanding of interface electron transport and molecular configuration evolution, which change the product turnover and even selectivity. Finally, I will demonstrate some strategies to control interfacial aggregated state, such that efficient and controllable two-electron and multi-electron reduction can be attained, particularly in the challenging environment of acidic conditions.