Fabrication of Carbon Electrodes Modified with Two Metal Porphyrinsand Electrochemical Reduction of CO2 Using the Electrodes

摘要

Catalysts for electrolytic reduction of CO2 have been studied as a means of storingrenewable energy.1 Wu reported that CO2 electrolytic reduction was observed at the electrodeon which the Zn porphyrin complex was immobilized.1 Their results indicate that theimmobilization had some sort of cooperative effect.We examined electrochemical reductionof CO2 on electrodes having immobilized porphyrin complexes with two different centralmetals,Cu and Zn.Cu porphyrin acts as a reduction catalyst that transfers electrons to CO2,2and Zn porphyrin complex acts as a Lewis acid that stabilizes the reduced form of CO2.We have synthesized two metal porphyrin complexes (Cu porphyrin and Zn porphyrin),asshown in Figure 1.The Porphyrins are designed with a highly hydrophobic 2-ethylhexylgroup to form a strong interaction with the carbon electrode.We used carbon paper as theelectrodes with high surface area.We dropped the solution to the electrode and dried it toproduce a modified electrode.We observed the surface of this electrode by SEM andmeasured cyclic voltammetry using this electrode.