Electrochemical Reduction of Carbon Dioxide to Carbon Monoxide Using CVD N-Doped Graphene on Copper Foam As Carbo-/Electro-Catalyst

Abstract

Nowadays, the increasing concentration of CO2 emission in our atmosphere is a serious environmental issue. According to an issue for preserving Earth’s Climate in the 13th UN Sustainable Development Goal, technologies that reduce both the carbon emissions of existing processes and those that efficiently utilize CO2 as feedstock for chemicals and fuels are necessarily required. Electrochemical reduction of CO2 (CO2R) is a promising method for converting this greenhouse gas into value-added products, utilizing renewable energy. A limitation is that CO2 is inert molecule () that requires considerable energy for chemical activation. In addition, the CO2R includes multiple steps of electron and proton transfer on catalyst surface. In general, the reduction potentials and product distribution for CO2R depend on experimental conditions, electrolytic solutions, and electrode materials. Herein, we used CVD nitrogen‐doped graphene on copper foam as carbo-/electro-catalyst (N-GP/Cu). To understand the selectivity of the as-prepared catalyst, we observe the electrochemical reduction product from CO2R using a combination of cyclic voltammetry (cv) and on-line mass spectrometry (DEMS). The presence of nitrogen heteroatom on the graphene sheet reduces the onset potential at ca. 0.5 V (vs. SCE) in 0.1M KHCO3 under CO2 gas. The N-GP/Cu can mainly convert CO2 into CO. We hope that this study may provide a guideline to develop the improved CO2 conversion catalyst.