Dopant-induced electron localization drives CO2 reduction to C2 hydrocarbons

• Published in: Nature chemistry Vol. 10; no. 9; pp. 974 - 980
• Main Authors: Zhou, Yansong, Che, Fanglin, Liu, Min, Zou, Chengqin, Liang, Zhiqin, De Luna, Phil, Yuan, Haifeng, Li, Jun, Wang, Zhiqiang, Xie, Haipeng, Li, Hongmei, Chen, Peining, Bladt, Eva, Quintero-Bermudez, Rafael, Sham, Tsun-Kong, Bals, Sara, Hofkens, Johan, Sinton, David, Chen, Gang, Sargent, Edward H.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-09-2018; Nature Publishing Group
• Subjects: 639/638/161/886; 639/638/77/886; Analytical Chemistry; Biochemistry; Boron; Carbon; Carbon dioxide; Catalysis; Catalysts; Chemical reduction; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Conversion; Copper; Copper converters; Dimerization; Electrochemistry; Electronic structure; Hydrocarbons; Inorganic Chemistry; Localization; Organic Chemistry; Oxidation; Physical Chemistry; Valence
• ISSN: 1755-4330; 1755-4349
• DOI: 10.1038/s41557-018-0092-x

The electrochemical reduction of CO
2
to multi-carbon products has attracted much attention because it provides an avenue to the synthesis of value-added carbon-based fuels and feedstocks using renewable electricity. Unfortunately, the efficiency of CO
2
conversion to C
2
products remains below that necessary for its implementation at scale. Modifying the local electronic structure of copper with positive valence sites has been predicted to boost conversion to C
2
products. Here, we use boron to tune the ratio of Cu
δ+
to Cu
0
active sites and improve both stability and C
2
-product generation. Simulations show that the ability to tune the average oxidation state of copper enables control over CO adsorption and dimerization, and makes it possible to implement a preference for the electrosynthesis of C
2
products. We report experimentally a C
2
Faradaic efficiency of 79 ± 2% on boron-doped copper catalysts and further show that boron doping leads to catalysts that are stable for in excess of ~40 hours while electrochemically reducing CO
2
to multi-carbon hydrocarbons.
On copper catalysts, Cu
δ+
sites play a key role in the electrochemical reduction of CO
2
to C
2
hydrocarbons, however, they are prone to being reduced (to Cu
0
) themselves. Now, a Cu
δ+
-based catalyst is reported that is stable for in excess of ~40 hours while electrochemically reducing CO
2
to multi-carbon hydrocarbons and that exhibits a Faradaic efficiency for C
2
of ~80%.