(507b) DFT Studies of the Electrochemical Reduction of CO2 to Alcohols On Cu/ZnO Catalysts

Within the DOE CALCD EFRC we have an integrated experimental and theoretical effort to develop novel catalysts for the electrochemical reduction of CO₂ to alcohols. There are several challenges to accurately model these systems such as the aqueous electrochemical environment, the changes to the catalyst structure under reaction conditions, the multiple possible reaction pathways and possible catalyst candidates. We have focused our initial modeling work on understanding CO₂ reduction on Cu/ZnO catalysts, which experimental results in our EFRC shows to be selective to methanol with improved activity versus Cu metal and Cu oxides. We have applied density functional theory (DFT) with free energy corrections for the aqueous electrochemical environment to examine CO₂ reduction pathways on various models of Cu on ZnO(10-10). These results will be compared with recent results from the Norskov group on stepped Cu surfaces.While these DFT studies provide insight into possible critical mechanisms on Cu/ZnO, they suffer from the computational cost of electronic-structure calculations. To be able to probe more realistic models of Cu on ZnO in a rapid manner we are developing charge optimized many body (COMB) potentials with Dr. Sinnott’s group at University of Florida to describe hydrocarbon chemistry on Cu/ZnO interface. We will present our progress in applying COMB potentials to examine CO₂ chemistry on Cu/ZnO surfaces through direct comparison with DFT studies of the same model surfaces.