Mixed Perovskite Phases of BaTiO3/BaTi5O11 for efficient Electrochemical Reduction of CO2 to CO.

Abstract

One of the most promising approaches in solving the energy crisis and reducing atmospheric CO2 emissions is artificial photosynthetic CO2 reduction. The electrochemical method for CO2 reduction is more appealing since it can be operated under ambient conditions, and the product selectivity strongly depends on the applied potential. Perovskites with ferroelectric properties strongly adsorb linear CO2 molecules. In this study, barium titanate (BaTiO3) perovskite is used as an electrocatalyst to promote CO2 activation and conversion to CO. Perovskite catalysts were prepared by ball-milling followed by annealing at 900 °C for 4 to 6 h in an open atmosphere. The TEM and SEM study shows that the particle size varies in the range of 80-200 nm. Mixed phases of BaTiO3 and BaTi5O11 supported on nitrogen-doped carbon nanotubes are found to be highly active for electrocatalytic CO2 reduction to CO with maximum Faradaic efficiency of 89.4% at -1.0 V versus Ag/AgCl in CO2 saturated 0.5 KOH solution. This study concludes that mixed phases of BaTiO3 and BaTi5O11 are more active and highly selective for CO2 conversion to CO compared to single-phase BaTiO3.