Simultaneous electrocatalytic reduction of dinitrogen and carbon dioxide on conducting polymer electrodes

The conversion of carbon dioxide with nitrogen containing compounds into valuable materials consistings of CN bond is a very attractive research area due to today’s energy requirements. The simultaneous electrocatalytic reduction of carbon dioxide and dinitrogen was investigated at 60 bar (30 bar N2 + 30 bar CO2) in this study. The electrochemical reduction was achieved on polyaniline (PAni) and polypyrrole (PPy) coated platinum electrodes at −0.165 V, the lowest possible overpotentials, known in the literature. The main products from the CO2 and N2 reduction were ammonia, urea and formic acid. The electrochemical reduction performed in an aqueous 0.1 M Li2SO4/0.03 M H+ solution was characterized by using cyclic voltammetry, potentiostatic electrolysis and Tafel diagrams in order to analyze the polymer selectivity as well as its reactivity as a function of the applied potential. Hence, CO2 and N2 were converted into value added chemicals, which included urea; an important raw material for the chemical industry with high nitrogen content.