Electrocatalytic reduction of CO2 with N/B co-doped reduced graphene oxide based catalysts

Abstract

Metal based materials are frequently used in electrocatalytic processes for the mitigation of CO2 emissions, increasing the cost of the technology and the toxicity of the material. Metal-free catalysts appear as an interesting alternative. This work focusses on the synthesis of nitrogen and boron doped reduced graphene oxide (rGO) for the electrocatalytic reduction of CO2 in gas phase in continuous operation mode in a PEM type cell. The main reaction products observed have been formic acid and CO, being the first one mainly formed. Results obtained with rGONB have been compared with the undoped rGO and with copper-based catalysts (Cu/rGO and Cu/rGONB). The non-metal doped material (rGONB) is much more active in the CO2 electrocatalytic reduction as compared with the undoped material (rGO). The catalytic activity of rGONB is very similar to those obtained with Cu/rGO and Cu/rGONB catalysts, pointing out rGONB as a very promising material for the electrocatalytic reduction of CO2. This is especially relevant considering that rGONB has been tested in a relatively high geometric area (compared with most works in literature), in gas phase and in continuous operation mode, which is an important step to carry out the further scale-up of the process for industrial applications.