Preparation of Highly Dispersive and Stable Platinum Catalysts Supported on Siliceous SB A-15 Mesoporous Material: Roles of Titania Layer Incorporation and Hydrogen Peroxide Treatment

摘要

Roles of titania layer incorporation and hydro gen peroxide treatment in the preparation of highly dispersed platinum catalysts supported on siliceous SBA-15 meso porous materials were studied by examining the catalysts at each step of the preparation. XRD, TEM, XPS, Raman, IR, CO chemisorptions, EXAFS and XANES techniques were employed to the investigation of the physico-chemical states of platinum and titanium. The platinum particles were uni formly dispersed on SBA-15 ranged from 1 to 2 nm in size by incorporating titania onto the surface of SBA-15 and then treating the impregnating platinum precursor with hydrogen peroxide, even at platinum loading as high as 4 wt.%. The platinum catalysts showed considerably higher catalytic activity in the combustion reactions of both carbon mon oxide and methane, suggesting a suitable catalyst for purifying diesel engine exhaust.