Boron and nitrogen co-doped carbon nanosheets encapsulating nano iron as an efficient catalyst for electrochemical CO 2 reduction utilizing a proton exchange membrane CO 2 conversion cell.

Electrochemical carbon dioxide (CO ₂ ) reduction, ideally in an aqueous medium, accounts for the sustainable storage of energy from renewable sources in the form of chemical energy in fuels or value-added chemicals. Herein, we report boron and nitrogen co-doped carbon nanosheets encapsulating iron nanocrystals (Fe/BCNNS) as a low cost, highly efficient and precious-metal-free electrocatalyst for the electrochemical reduction of carbon dioxide to formic acid. The porous architecture of the boron and nitrogen co-doped carbon nanosheets along with the active Fe-N _x , N and B sites synergistically allow better three phase contact to enhance the electrocatalytic activity of the cell. Both half-cell as well as full cell measurements have been performed with this particular catalyst. The proton exchange membrane (PEM) CO ₂ conversion cell is tested under a continuous flow of CO ₂ gas and is demonstrated to selectively produce a high yield of formic acid due to improved interaction between the catalyst and gas molecules. The maximum yield of formic acid achieved is as high as 94% after 60 min of reaction with Fe/BCNNS as both anode and cathode catalysts. It can be anticipated that such a facile synthesis strategy and excellent electrocatalytic performance of low-cost Fe/BCNNS catalyst can be easily scaled up for industrial applications in electrochemical CO ₂ conversion.
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