A gold-based nanostructure has been demonstrated as promising materials for the selective electroreduction of CO2 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 CO2 in 0.5 m NaHCO3 . 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.

International audienceA novel colloidal catalyst was developed through the encapsulation of cuprous oxide nanoparticles in polydiacetylene micelles. The Cu-based catalyst was applied to the Huisgen cycloaddition reaction in fully aqueous medium. The process neither requires heating nor controlled atmosphere and the catalyst can be recycled in subsequent reactions without any loss of activity