Controlled pore size of Pt/KIT-6 used for propane total oxidation

Mesoporous silica KIT-6 with different pore sizes was controllably synthesized by hydrothermal meth- ods. The same contents of Pt were loaded on KIT-6 sup- ports to apply for propane total oxidation. Low-angle X-ray diffraction （XRD）, nitrogen adsorption-desorption, CO chemisorption and transmission electron microscopy （TEM） were carried out to investigate the physicochemical properties of the catalysts. The results reveal that different pore sizes of KIT-6 supports could affect the Pt particle sizes on KIT-6. The mesopores on KIT-6-80 and KIT-6- 130 effectively confine the size of the inside Pt nanopar- ticles during calcining. Pt/KIT-6-80 with the appropriate pore size as well as the Pt particle size exhibits the best catalytic performance with T50 （the temperature at which hydrocarbon （HC） conversion reaches 50%） of only 237 ℃. However, Pt particles prefer dispersing on the external surface of KIT-6-40 due to those too small pores.