Cu and Cu alloy electrodes for conversion of CO2 to value-added hydrocarbon fuels

Abstract

The electrochemical reduction of CO2 to valuable chemicals or fuel can represent a solution for reducing the carbon footprint and closing the unbalanced carbon-cycle. Among currently available materials, Cu based catalyst has been reported to be albe to convert CO2 to various hydrocarbons. However, for its practical implementation, much better selectivity and low overpotential of cathode than that of current state of art is required. Particularly, the production of high-quality hydrocarbon fuels from the cathodic CO2 reduction reaction is the most essential requirement in that those chemicals have high energy contents and compatibility with the existing fuel infrastructure and thereby, can make the overall reaction highly beneficial. To accomplish the ultimate production of value-added hydrocarbon fuels from the abundant and inexpensive CO2, it is critical to control C-C coupling kinetics and its detailed reaciton pathway. <br/> Chapter 2 investigates Cu mesopore electrodes with various pore size and depth as a potential candidate for selectively controlling CO2 to C2 chemical formation and reaction kinetics. While most metal catalysts produce C1 species, such as CO and HCOOH, various hydrocarbons and alcohols comprising more than two carbons have been achieved using Cu based catalysts only. Methods for producing specific C2 reduction outcomes with high selectivity, however, are not amenable thus far. In this work, the morphology effect of a Cu mesopore electrode on the selective production of C2 products, C2H4 or C2H6, is presented. The Cu mesopore electrodes with precisely controlled pore widths and depths were prepared by a thermal deposition process on anodized alumina oxide. By this simple synthesis method, we demonstrated that C2 chemical selectivity can be tuned by systematically altering the morphology. Moreover, supported by computational simulation, we proved that nanomorphology can change the local pH and additionally, retention time of key intermediates by confining the chemicals inside the pore. <br/> Chapter 3 investigates CO2 to value-added hydrocarbon fuel conversion on Cu alloy electrode. Natural photosynthesis has ability to produce glucose and its derivatives from CO2