Production of oxalic acid by electrochemical reduction of CO2 using silver-carbon material from babassu coconut mesocarp

Abstract The present study provides an efficient carbon dioxide (CO2) reduction process to produce oxalic acid with approximately 29% faradaic efficiency (based on HPLC) using a carbon material from babassu biomass coupled with silver. A new carbon-silver hybrid material has been prepared from babassu mesocarp by hydrothermal carbonization; this material initiates the electrochemical reduction of CO2 at a lower potential and catalyzes the conversion of CO2 into oxalic acid. To evaluate the catalytic potential of this reaction, other materials, such as glassy carbon and hydrothermal carbon, which generated a higher cathodic current density, were tested at the same potential. The rate of CO2 reduction was found to be increased at low potentials in the presence of the hybrid carbon-silver material synthesized by a one-pot hydrothermal method from babassu biomass in 48 h (Ag@C-48).