Enhancement of CO 2 Conversion With Biochar in Dielectric Barrier Discharge

ABSTRACT Green and low‐cost biochar (bamboo charcoal biochar: BCB; walnut shell biochar: WSB) has been employed in a dielectric barrier discharge reactor to enhance CO 2 conversion performance. Packing WSB delivers the highest CO 2 conversion of 17.9% with a stable CO selectivity of approximately 139% at 9.0 kV. The superior performance of WSB compared to BCB is attributed to larger specific surface area, more basic sites, and higher contents of defects and ketone groups, which provide abundant active sites for CO 2 adsorption and activation. Additionally, packing WSB leads to higher discharge power and enhanced charge characteristics, supplying more reactive species to promote reaction. It is deduced that biochar participates continuously in the reaction and establishes a pseudo‐steady state to produce CO‐rich products.