ELECTROCATALYTIC ACTIVITY OF COIITPP-PYRIDINE COMPLEX MODIFIED CARBON ELECTRODE FOR CO2 REDUCTION

A cobalt(II)tetraphenylporphyrin (CoIITPP)-pyridine complex modified glassy carbon electrode (CoTPP/py/GC) was prepared and characterized in the form of CoIITPP-py-NHCO-GC. The catalytic activity for the electrochemical reduction of CO2 was studied in phosphate buffer; the electrode showed a high catalytic activity for CO2 reduction to CO at potentials more negative than -1.0 V vs. SCE (-0.4 V vs. RHE), with a current efficiency of 92% for CO production at -1.1 V vs. SCE. CoTPP/py/GC also showed a high durability of the catalytic activity and the overall turnover number (mol of CO produced/mol of CoIITPP on GC) exceeded 10(7). The role of the pyridine in CoTPP/py/GC is discussed in connection with the activity and stability as an electrode.