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

Abstract

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 CO 2 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 CO 2 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.

Cutting-Edge Electrocatalysts for CO2RR

“…Carbon-based materials, including porous carbon, graphene, carbon nanotubes, and modified diamond, have shown different performances for CO 2 reduction due to their different crystallinity, surface area, tunable chemical and physical properties, and good conductivity [38]. For instance, oxide carbon nanotubes can selectively convert CO 2 into acetic acid with a faradaic efficiency of 71.3% [39]. However, from an economic perspective, the cost of these materials makes them not economically advantageous for practical applications; e.g., the price of 5 g of carbon nanotubes can range from GBP 59 to 259 [40].…”

In situ electrochemical characterization of CuxO-based gas-diffusion electrodes (GDEs) for CO2 electrocatalytic reduction in presence and absence of liquid electrolyte and relationship with C2+ products formation

“…S1 and scheme in Fig. S2a in the SI) [60][61][62]. More in detail, the copper-based electrode (working electrode, 1 × 1 cm) was immersed in 0.1 M KHCO3 aqueous electrolyte, while a platinum ring was used as the counter-electrode, located at the anode compartment separated from the cathode by a proton exchange membrane (Nafion® 115, supplied by Ion Power) and working in 0.1 or 3.6 M KHCO3 aqueous electrolyte.…”