Effect of Carbon Deposits on the Structure of Hybrid C/TiO/SiO Adsorbents

Abstract

The structural characteristics of pyrocarbon/X (X = fumed silica, mesoporous silica gel, fumed titania/silica, CVD-TiO 2 /fumed silica, CVD-TiO 2 /silica gel) prepared using several precursors [CH 2 Cl 2 , cyclohexene and TiO(AcAc) 2 , where Ac = acetylacetonate] were studied using the nitrogen adsorption/desorption method and an improved technique to allow the calculation of pore size distributions applying regularization procedures. Various pore models were used for the carbon phase. The pyrocarbon structure and distribution on the TiO 2 /SiO 2 supports depends primarily on the structural features of the titania phase which exhibits catalytic activity in the pyrolysis of organic materials. The formation of relatively large concentrations of pyrocarbon typically reduces the porosity and specific surface area of the hybrid adsorbents produced.