Reactions of ethane with CO2 over supported Au

The dehydrogenation of C2H6 and its reaction with CO2 have been investigated on Au deposited on various oxides. Both reactions occurred at relatively high temperatures, above 650 K. Ethylene formed in the dehydrogenation process with high selectivity, 94-98%, on most of the catalysts. The conversion of C2H6 varied with the nature of support and fell in the range of 3-19%. Adding CO2 to C2H6 only slightly influenced the reaction of C2H6 on Au/MgO and Au/Al2O3, but markedly increased the conversion of C2H6 and changed its reaction pathways on Au deposited on n-type TiO2, CeO2 and ZnO. Taking into account the properties of these oxides, we came to the conclusion that their electric behavior and not their defect structure play a dominant role in the enhanced activity of Au deposited on these supports. Based on the different work functions, an electronic interaction between Au particles and these oxides is proposed, which facilitates the formation of reactive negatively charged CO2. (C) 2015 Elsevier Inc. All rights reserved.