Hydrogen production by water splitting with Al and in-situ reduction of CO₂ into formic acid

The utilization of CO₂ as a carbon source to produce useful chemicals could be regarded as a promising way to reduce CO₂ emissions and to minimize global warming. In this study, hydrogen obtained by water spilling with Al was used for in-situ reduction of CO₂ into formic acid. The common bulk Al was employed as a reducing agent to split water for reduction of CO₂, possessing safe and convenient advantages. Results revealed that the hydrogen production from water with the oxidation of Al can be enhanced in the presence of NaHCO₃, as a source of CO₂, which can be in-situ reduced into formic acid. A considerable high formic acid yield of 64% with near 100% selectivity was achieved. Additionally, experiments of mix-metals containing Fe, Al, Cu. Zn and Sn with NaHCO₃ were conducted to investigate the Electronic waste (E-waste) as reductant for reducing CO₂ and more than 60% yield of formic acid were obtained, indicating that CO₂ reduction by waste metal is feasible. This study can assist in developing an efficient and economical process for conversion of CO₂ to value-added chemicals.