Supported metallic nanoparticles prepared by an organometallic route to boost the electrocatalytic conversion of CO2

Electrocatalysts based on metal nanoparticles (metal =Ru, Fe and Pt), prepared by an organometallic (OM) route, and supported on carbon nanotubes (CNTs), have been studied in the electro-catalytic reduction of CO2 in comparison with those prepared using inorganic salts to deposit the metal nanoparticles (NPs) over CNTs (INORG route). The OM route allows to obtain electrocatalysts with superior performances in terms of productivity and especially turnover frequency, with an enhanced formation of C1 products (methanol and formic acid) with respect to C2+products (acetic acid, acetone, isopropanol and ethanol). Particularly for Ru samples, there is an increase up to nearly two order of magnitude in the cumulative TOF with respect to a sample with an equivalent metal loading and mean particle size but prepared by the INORG route. Carbon selectivity to methanol reaches the interesting value of 65 %. The analysis of this intrinsic boosting of both activity and selectivity in the electrocatalytic reduction of CO2 suggests a role in this enhanced performance of small oxide patches on the metal nanoparticles formed as residues of the process of removal of the ligands present in the OM route.