Coverage-driven selectivity switch from ethylene to acetate in high-rate CO2/CO electrolysis

Pengfei Wei; Dunfeng Gao; Tianfu Liu; Hefei Li; Jiaqi Sang; Chao Wang; Rui Cai; Guoxiong Wang; Xinhe Bao

doi:10.1038/s41565-022-01286-y

Coverage-driven selectivity switch from ethylene to acetate in high-rate CO₂/CO electrolysis

Nat Nanotechnol. 2023 Mar;18(3):299-306. doi: 10.1038/s41565-022-01286-y. Epub 2023 Jan 12.

Authors

Pengfei Wei^#^{1

2}, Dunfeng Gao^#¹, Tianfu Liu^#¹, Hefei Li^{1

2}, Jiaqi Sang^{1

2}, Chao Wang^{1

2}, Rui Cai¹, Guoxiong Wang³, Xinhe Bao⁴

Affiliations

¹ State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China.
² University of Chinese Academy of Sciences, Beijing, China.
³ State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China. wanggx@dicp.ac.cn.
⁴ State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China. xhbao@dicp.ac.cn.

^# Contributed equally.

PMID: 36635334
DOI: 10.1038/s41565-022-01286-y

Abstract

Tuning catalyst microenvironments by electrolytes and organic modifications is effective in improving CO₂ electrolysis performance. An alternative way is to use mixed CO/CO₂ feeds from incomplete industrial combustion of fossil fuels, but its effect on catalyst microenvironments has been poorly understood. Here we investigate CO/CO₂ co-electrolysis over CuO nanosheets in an alkaline membrane electrode assembly electrolyser. With increasing CO pressure in the feed, the major product gradually switches from ethylene to acetate, attributed to the increased CO coverage and local pH. Under optimized conditions, the Faradaic efficiency and partial current density of multicarbon products reach 90.0% and 3.1 A cm^-2, corresponding to a carbon selectivity of 100.0% and yield of 75.0%, outperforming thermocatalytic CO hydrogenation. The scale-up demonstration using an electrolyser stack achieves the highest ethylene formation rate of 457.5 ml min^-1 at 150 A and acetate formation rate of 2.97 g min^-1 at 250 A.

Abstract

Grants and funding