DFT Modeling of Cu-Catalyzed CO to EtOH Conversion

Renewable energy is a viable alternative to fossil fuels and addresses increasing concerns over climate change. Methods of ethanol production have been studied to develop a sustainable model for widespread use and to curb the use of environmentally adverse fuel sources. One such method of production is the copper-catalyzed conversion of carbon monoxide into ethanol. Conventional ethanol production is burdensome with regards to land and water requirements, neither of which would be needed in appreciable amounts for the aforementioned conversion process. In addition to creating a closed loop CO to fuel system, the process would also offset the carbon balance. Cu(211) was chosen to determine its viability and effectiveness as a surface catalyst for CO conversion.  A series of reaction intermediates that manifest in the CO to EtOH conversion process were modeled on the Cu(211) surface and their corresponding lowest-energy configurations were found. A potential energy surface was generated to yield thermodynamic information about the chosen surface catalyst. It was found that after the rate-determining CO dissociation step was overcome, the successive hydrogenation steps that occurred in the conversion process were relatively thermodynamically stable. Solvation effects, electric potential, zero potential energy, and entropy of vibrational effects were also taken into consideration. When compared to the Cu(100) surface, the Cu(211) surface was found to be more energetically favorable as well as thermodynamically stable. Thus, Cu(211) could feasibly be used to produce ethanol for energy consumption.