Sol–gel synthesis, texture and catalytic activity of titania–silica sorbents

Abstract

Sol–gel synthesis of mesoporous titania–silicas with the structure related to Type MCM-41 is carried out. The method of nitrogen adsorption has established influence of fluoride-anion on the adsorptive and catalytic properties of titania–silica. The pore structure in titania–silica is in the form of an hexagonal array of uniform tubular channels. Asymptotic increase in a specific surface area of titania–silica catalyst with growth of F/Si ratio is shown. Both silicas and titano-silicas showed catalytic activity in the reaction of isomerization of α-pinene epoxide. The largest activity (100% conversion) and selectivity for campholenic aldehyde (57%) was shown by titanosilicate synthesized at Ti/Si = 25/75 and F/Si = 0.4. Isotherms of nitrogen low-temperature adsorption-desorption and PSD curves for titania-silicas (7, 12) and silica (6) received at presence of fluoride-anion in ratio of F/Si equal: 7–0, 6–0.4, 12–0.4 mol/mol.