Silver nanoparticles supported on zirconia-ceria for the catalytic wet air oxidation of methyl -butyl ether

In this work Ag nanoparticles supported on ZrO 2 -CeO 2 promoted with different amounts of CeO 2 (0, 0.5, 1, 5, 10, 15 and 20 wt%) were synthesized by deposition-precipitation method in order to test the Catalytic Wet Air Oxidation (CWAO) of Methyl Tert -Butyl Ether (MTBE). X-ray diffraction patterns reveal that the tetragonal ZrO 2 phase (t-ZrO 2 ) present in the catalysts is stabilized by the presence of CeO 2 , forming a solid solution, and preventing transformation to the monoclinic phase (m-ZrO 2 ). The t-ZrO 2 stability and the dispersion of Ag on ZrO 2 increase with CeO 2 concentration. HRTEM images confirmed that the mean crystallite size of supports and monometallic Ag catalyst decreases by CeO 2 addition. CeO 2 can also improve the reduction of Ag 2 O and increase also the d-electron density of the surface silver atoms. Furthermore, CeO 2 has a promoting effect on silver supported zirconia-ceria because of the strong metal-support interaction and its relationship of oxygen vacancies of zirconia-ceria support. The extent of reduction of silver controls the quantity of oxygen to be adsorbed during the catalytic oxidation reaction. In general, a small crystal size and high metallic dispersion can enhance the activity of MTBE catalytic wet air oxidation. The Ag/ZrO 2 -(15%)CeO 2 catalyst was the most active with 90% MTBE conversion. In this work Ag nanoparticles supported on ZrO 2 -CeO 2 promoted with different amounts of CeO 2 were synthesized by deposition-precipitation method in order to test the Catalytic Wet Air Oxidation (CWAO) of Methyl Tert -Butyl Ether (MTBE).