A continuous semi-micro reactor prototype for electrochemical reduction of CO2 into formic acid

In this article, we have reported the electrochemical reduction of CO2 in a continuous semi-micro reactor for the synthesis of formic acid (HCOOH). The reactor was fabricated with polydimethylsiloxane by following the microwire molding technique. Tin (Sn) nanocatalyst-deposited graphite rod was used as the cathode for the electrochemical reduction of CO2 to HCOOH. We performed the reactions in an alkaline environment at different pH values and different applied voltages for 1200 s to obtain an optimum condition for HCOOH production. The maximum Faradaic efficiency (FE) values of 84.25 and 57.69% were obtained at 2.5 and 3 V, respectively, after 300 s at an initial pH value of 9.5. It was found that the continuous reactor showed higher FE values than the batch reactor. It was also noted that the HCOOH concentration in the batch reactor was continuously decreasing with time, whereas it was almost constant in the continuous semi-micro reactor.