Sulfur-Decorated Ni-N-C Catalyst for Electrocatalytic CO2 Reduction with Near 100 % CO Selectivity

Developing highly efficient electrocatalysts for electrochemical CO2 reduction (ECR) to value-added products is important for CO2 conversion and utilization technologies. In this work, a sulfur-doped Ni-N-C catalyst is fabricated through a facile ion-adsorption and pyrolysis treatment. The resulting Ni-NS-C catalyst exhibits higher activity in ECR to CO than S-free Ni-N-C, yielding a current density of 20.5 mA cm(-2) under -0.80 V versus a reversible hydrogen electrode (vs. RHE) and a maximum CO faradaic efficiency of nearly 100 %. It also displays excellent stability with negligible activity decay after electrocatalysis for 19 h. A combination of experimental investigations and DFT calculations demonstrates that the high activity and selectivity of ECR to CO is due to a synergistic effect of the S and Ni-N-X moieties. This work provides insights for the design and synthesis of nonmetal atom-decorated M-N-C-based ECR electrocatalysts.

Automated summary

In this research, a sulfur-doped Ni-N-C catalyst was successfully synthesized through a facile ion-adsorption and pyrolysis treatment. This catalyst showed higher activity and selectivity in electrochemical CO2 reduction (ECR) to CO, along with excellent stability. The synergetic effect between sulfur and Ni-N-X moieties was identified as the key factor contributing to the high activity and selectivity.