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 C-N 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 N-2+30 bar CO2) in this study. The electrochemical reduction was achieved on polyaniline (PAni) and polypyrrole (PPy) coated platinum electrodes at -0.165V, the lowest possible overpotentials, known in the literature. The main products from the CO2 and N-2 reduction were ammonia, urea and formic acid. The electrochemical reduction performed in an aqueous 0.1 M Li2SO4/0.03 MH+ 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 N-2 were converted into value added chemicals, which included urea; an important raw material for the chemical industry with high nitrogen content.