CO 2 Reduction to CO in Water: Carbon Nanotube–Gold Nanohybrid as a Selective and Efficient Electrocatalyst

A gold‐based nanostructure has been demonstrated as promising materials for the selective electroreduction of CO 2 to CO in aqueous conditions. In this work, we present a carbon nanotube–gold nanohybrid as a selective and efficient electrocatalyst for the reduction of CO 2 in 0.5  m NaHCO 3 . The hybrid material exhibits remarkable activity with a current density of 10 mA cm −2 at −0.55 V versus standard hydrogen electrode with a stable CO production rate (0.52 μmol s −1 ) after 4 h electrolysis. Monodispersed gold nanoparticles anchored on carbon nanotubes through a layer‐by‐layer method allows very little Au loading and thus minimization of the cost of electrode fabrication with a mass activity up to 100 A g −1 at −0.55 V versus reversible hydrogen electrode. It is 33 times higher than a previous report for monodisperse Au nanoparticles (3 A g −1 ) while ensuring selectivity (70 % faradaic yield of CO) at comparable reduction potential.