Photoreduction of carbon dioxide by ultraviolet light in the presence of copper titanium oxide photocatalyst in CuCl₂ solution

The application of a UV/photocatalyst catalyst process to convert the greenhouse air pollutants, i.e., CO₂, to useful chemicals was studied. The emission of CO₂ to the atmosphere was substantially found in the industrial waste gaseous streams. The photocatalysts used were Ag/TiO₂ and Cu/TiO₂ prepared by impregnation method. The photocatalytic reductions of CO₂ were performed via three different methods. The major product via methods 1 and 2 was methanol. An addition of CuCl₂ to the solution containing suspended Cu/TiO₂ catalyst could produce CuCl/Cu/TiO₂, which further catalytically enhanced the reduction of CO₂ and CH₃OH, producing CH₄ and increasing its yield. The determining step for the production of methane was the additions of Na₂CO₃ and CuCl₂ in the aqueous solution. The orders of concentrations of Na₂CO₃ enhancing the methane yields were 0.1 > 0.2 > 0.3 > 0.05 M Na₂CO₃ at 0.1 M CuCl₂. Thus, the process is environmentally favorable. This is an abstract of a paper presented at the AWMA's 99th Annual Conference and Exhibition (New Orleans, LA 6/20-23/2006).