Electrocatalytic Study of Carbon Dioxide Reduction By Co(TPP)Cl Complex

Khalaf Alenezi

doi:10.1155/2016/1501728

Abstract

Carbon dioxide (CO2) is notorious for being a greenhouse gas and is the most important cause of global warming. However, it can be converted into useful products as it is a source of carbon. Reduction of CO2is therefore an attractive research topic for many chemists. Different methods of electrocatalytic reduction of CO2have been reported previously. Since CO2is very stable, the direct electroreduction of CO2into CO requires high potential at −2.2 V versus Ag/AgCl. In this work, CO2reduction was carried out by the photoelectrocatalysis of CO2in the presence of cobalt(III)tetraphenylporphyrin [Co(TPP)Cl] at −1.85 V with a current efficiency of 71%. At illuminated p-type silicon photocathode, the reduction of CO2into CO was performed at a potential of 300 mV which is positive. However, at the same conditions, potential of −1.55 V with a current efficiency ofca65% is required for the carbon electrode.

Highlights

The increasing amount of carbon dioxide (CO2) over the past years may affect the environment adversely due to the fact that it is a greenhouse gas and can lead to global warming
Energy is required for all these processes, such as requirement of electricity in electrochemical reduction process [11]
The electrocatalytic behavior of Co(TPP)Cl was tested by cyclic voltammetry in the absence of CO2

Summary

Introduction

The increasing amount of carbon dioxide (CO2) over the past years may affect the environment adversely due to the fact that it is a greenhouse gas and can lead to global warming. CO2 is a final product of combustion of carbon-containing compounds and represents fully oxidized carbon. It is thermodynamically very stable and it requires a lot of energy to break its C-O bonds. Photosynthesis, photocatalytic, and electrochemical reduction of CO2 are the effective processes to use CO2 as a carbon source and convert it into useful products. CO2 has been converted into chemicals (such as formic acid) and fuels (such as methanol, methane, and carbon monoxide (CO)) previously [12,13,14]. Photochemical conversion of CO2 to fuels or valuable chemicals using renewable solar energy can decrease the amount of CO2 in the atmosphere [15]

Methods

Results

Conclusion