Highly efficient binary copper-iron catalyst for photoelectrochemical carbon dioxide reduction toward methane

Baowen Zhou; Pengfei Ou; Nick Pant; Shaobo Cheng; Srinivas Vanka; Sheng Chu; Roksana Tonny Rashid; Gianluigi Botton; Jun Song; Zetian Mi

doi:10.1073/pnas.1911159117

Highly efficient binary copper-iron catalyst for photoelectrochemical carbon dioxide reduction toward methane

Proc Natl Acad Sci U S A. 2020 Jan 21;117(3):1330-1338. doi: 10.1073/pnas.1911159117. Epub 2020 Jan 3.

Authors

Baowen Zhou^{1

2}, Pengfei Ou³, Nick Pant¹, Shaobo Cheng⁴, Srinivas Vanka^{1

2}, Sheng Chu², Roksana Tonny Rashid², Gianluigi Botton⁴, Jun Song⁵, Zetian Mi^{6

2}

Affiliations

¹ Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109.
² Department of Electrical and Computer Engineering, McGill University, Montreal, QC H3A0E9, Canada.
³ Department of Mining and Materials Engineering, McGill University, Montreal, QC H3A0C5, Canada.
⁴ Department of Materials Science and Engineering, Canadian Centre for Electron Microscopy, McMaster University, Hamilton, ON L8S4M1, Canada.
⁵ Department of Mining and Materials Engineering, McGill University, Montreal, QC H3A0C5, Canada; jun.song2@mcgill.ca ztmi@umich.edu.
⁶ Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109; jun.song2@mcgill.ca ztmi@umich.edu.

Abstract

A rational design of an electrocatalyst presents a promising avenue for solar fuels synthesis from carbon dioxide (CO₂) fixation but is extremely challenging. Herein, we use density functional theory calculations to study an inexpensive binary copper-iron catalyst for photoelectrochemical CO₂ reduction toward methane. The calculations of reaction energetics suggest that Cu and Fe in the binary system can work in synergy to significantly deform the linear configuration of CO₂ and reduce the high energy barrier by stabilizing the reaction intermediates, thus spontaneously favoring CO₂ activation and conversion for methane synthesis. Experimentally, the designed CuFe catalyst exhibits a high current density of -38.3 mA⋅cm^-2 using industry-ready silicon photoelectrodes with an impressive methane Faradaic efficiency of up to 51%, leading to a distinct turnover frequency of 2,176 h^-1 under air mass 1.5 global (AM 1.5G) one-sun illumination.

Keywords: CO2 reduction; binary copper−iron catalyst; methane; photoelectrocatalysis.