Reactions of ethane with CO2 over supported Au.

The dehydrogenation of C 2 H 6 and its reaction with CO 2 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 C 2 H 6 varied with the nature of support and fell in the range of 3–19%. Adding CO 2 to C 2 H 6 only slightly influenced the reaction of C 2 H 6 on Au/MgO and Au/Al 2 O 3 , but markedly increased the conversion of C 2 H 6 and changed its reaction pathways on Au deposited on n -type TiO 2 , CeO 2 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 CO 2 . [ABSTRACT FROM AUTHOR]