Electrochemical Conversion of Carbon Dioxide to Useful Fuels Using Graphene-Based Catalytic Coatings

Yair Bochlin, Chemical Engineering, Ben Gurion University, Beer Sheva, Israel
Armand Bettelheim, Chemical Engineering, Ben Gurion University, Beer Sheva, Israel
Eli Korin, Chemical Engineering, Ben Gurion University, Beer Sheva, Israel


The sharply rising level of atmospheric CO2 is one of the largest environmental concerns facing our civilization today. The conversion of CO2 back to useful compounds is a critical goal that would restore balance to earth’s atmosphere, since CO2 is the most significant greenhouse gas. CO2 reduction is possible through chemical catalysis, electrochemistry, photochemistry and biological processes. Chemical catalytic processes generally operate at high temperatures and pressures which lead to high energy cost. Electrochemical methods, however, operate at ambient conditions which offer a simple and effective route for CO2 reduction.
The electrocatalytic capabilities toward CO2 reduction of some cobalt porphyrins have been reported in the literature, although at considerable overpotentials. The present work deals with the spectroscopic, microscopic and electrochemical examination of the interactions occurring between such porphyrins and graphene derivatives, and their effect on CO2 reduction. Such self-assembled systems which are formed between 5,10,15,20-Tetrakis(1-methyl-4-pyridinio) porphyrin (CoTMPyP) and graphene oxide (GO) were deposited on electrode surfaces (such as glassy carbon) by means of electrodeposition. TEM images show homogeneously distributed CoTMPyP in the graphene sheets.
The electrodeposited CoTMPyP-GO system showed increased activity for CO2 reduction vs. water reduction (1.2 and 0.25 mA/cm2, respectively, at -1.2V vs. Ag/AgCl), as examined in aqueous 0.1 M Na2CO3 solution at pH 11.5.