Modulating intermediate coverage of single-atom catalyst for kinetics-boosted CO2 electroreduction in membrane electrode assembly

• Published in: Chemical engineering science 2024-10, Vol.298, p.120314, Article 120314
• Main Authors: Zheng, Sixing, Liu, Yingnan, Yang, Xiaoxuan, Zhao, Zilin, Zhang, Qinghua, Yang, Bin, Li, Zhongjian, Dong, Chung-Li, Lei, Lecheng, Hou, Yang
• Format: Article
• Language: English
• Subjects: Boosting kinetics; CO2 electroreduction; Membrane electrode assembly; Modulating CO effective coverage; S-coordinated doping
• ISSN: 0009-2509
• DOI: 10.1016/j.ces.2024.120314

Intermediate effective coverage of single-atom catalyst is modulated to boost the reaction kinetics of CO2 electroreduction in membrane electrode assembly. [Display omitted] •Ni-NSC exhibits industrial-level current density in a membrane electrode assembly.•S-coordinated doping modulates the effective coverage of the key intermediate *CO.•Intermediate effective coverage is modulated to boost the CO2ER reaction kinetics. Developing high-efficiency electrocatalysts with low overpotential and industrial-level current density is crucial to CO2 electroreduction (CO2ER). However, the poor modulating of intermediate *CO effective coverage results in low selectivity of target product. Herein, a feasible strategy to modulate *CO effective coverage on isolated nickel sites through S-coordinated doping (Ni-NSC) is reported. Incorporation of S species in the coordination of Ni-NSC leads to a low-coordination state of center Ni atom, which enhances hybridization of the d band with the 2π* orbital of CO, improving CO coverage. As a result, Ni-NSC reaches an industrial-level current density of over 280 mA cm−2 in a membrane electrode assembly device, and realizes the maximum FECO above 95 %. Control experiments and characterizations reveal that the monovalent Ni atomic center in the Ni-NSC after S doping promotes the formation of reactive intermediate *COLFB and improves *CO effective coverage, thus boosting the CO2ER kinetics.