Effect of surface Ti3+ on the sol-gel derived TiO2 in the selective acetylene hydrogenation on Pd/TiO2 catalysts

The effects of calcination atmospheres (O-2 and N-2) and the preparation methods (impregnation and electroless deposition) on the physiochemical and catalytic properties of Pd/TiO2 catalysts were investigated in the selective hydrogenation of acetylene. The TiO2 supports calcined under O-2 or N-2 had similar crystalline phase, average crystallite size, and BET surface area, however, the amount of surface Ti3+ was significantly higher on the TiO2 calcined under N-2. The dispersion of Pd metal and the metal-support interaction were influenced by the presence of Ti3+ on the TiO2 surface, resulting in modification of their catalytic performances in the selective hydrogenation of acetylene. In the present study, high ethylene selectivity (similar to 92%) can be obtained at complete acetylene conversion (100%) over the 1% Pd/TiO2-N-2 prepared by electroless deposition method. (C) 2014 Elsevier B.V. All rights reserved.