Cost effective and scalable synthesis of supported Au nanoparticles for the electroreduction of CO₂ to CO

Various loadings of gold supported on carbon black (Au/CB) were synthesized via a simple and scalable one-pot process and then tested as catalysts for the electroreduction of CO₂ to CO. The bulk and surface properties of the Au/CB materials were characterized using XRD, TGA, XPS, TEM and HRTEM techniques. The synthesized Au nanoparticles are of average diameters ~10±2 nm and show a promising selectivity and energy efficiency. The electrochemical performance of some of the studied electrocatalysts (namely Au-40/CB and Au-50/CB) was as high as 93.5% selectivity toward CO over the undesired H2 evolution and specific CO current densities were in excess of -6 A/cm²-g (at -1.4 vs. Ag/AgCl). This study clearly shows that desirable performance for the electroreduction of CO₂ to CO is, certainly, achievable with Au/CB catalyst prepared by a low-cost route providing that the Au nanoparticles are suitably sized and deposited with the optimum wt% on the CB support.