Pd/Ga2O3 Al2O3 catalysts for the selective liquid phase hydrogenation of acetylene to ethylene
The structure of Ga2O3 Al2O3 supports and Pd/Ga2O3 Al2O3 catalysts and the performance of these catalysts in liquid phase acetylene hydrogenation have been investigated. The deposition of Ga(NO3)3 onto Al2O3 by impregnation followed by calcination of the impregnated support at 600degC yields g Ga2O3 Al2O3 solid solutions containing up to 50 wt Ga2O3. X ray diffraction characterization of model palladium catalysts and their temperature programmed reduction with hydrogen have demonstrated that, while palladium in Pd/Ga2O3 is in the form of a Pd2Ga alloy, in the Pd/g Ga2O3 Al2O3 catalyst there is no direct interaction between PdO and Ga2O3 particles and palladium is in the monometallic state. The introduction of 10 20 wt gallium oxide into Al2O3 lowers the activity of the supported palladium catalyst relative to that of the initial Pd/Al2O3 but increases the ethylene yield by enhancing the ethylene formation selectivity.
Kinetics and Catalysis