Highly Selective Electrochemical Reduction of CO₂ to Alcohols on an FeP Nanoarray

Abstract

Electrochemical reduction of CO₂ into various chemicals and fuels provides an attractive pathway for environmental and energy sustainability. It is now shown that a FeP nanoarray on Ti mesh (FeP NA/TM) acts as an efficient 3D catalyst electrode for the CO₂ reduction reaction to convert CO₂ into alcohols with high selectivity. In 0.5 m KHCO₃ , such FeP NA/TM is capable of achieving a high Faradaic efficiency (FE <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow></mml:mrow> <mml:mrow><mml:mi>CH</mml:mi> <mml:msub><mml:mrow></mml:mrow> <mml:mn>3</mml:mn></mml:msub> <mml:mi>OH</mml:mi></mml:mrow> </mml:msub> </mml:math> ) up to 80.2 %, with a total FE <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow></mml:mrow> <mml:mrow><mml:mi>CH</mml:mi> <mml:msub><mml:mrow></mml:mrow> <mml:mn>3</mml:mn></mml:msub> <mml:mi>OH</mml:mi> <mml:mo>+</mml:mo> <mml:mi>C</mml:mi> <mml:msub><mml:mrow></mml:mrow> <mml:mn>2</mml:mn></mml:msub> <mml:mi>H</mml:mi> <mml:msub><mml:mrow></mml:mrow> <mml:mn>5</mml:mn></mml:msub> <mml:mi>OH</mml:mi></mml:mrow> </mml:msub> </mml:math> of 94.3 % at -0.20 V vs. reversible hydrogen electrode. Density functional theory calculations reveal that the FeP(211) surface significantly promotes the adsorption and reduction of CO₂ toward CH₃ OH owing to the synergistic effect of two adjacent Fe atoms, and the potential-determining step is the hydrogenation process of *CO.