Crystallization of TS-1 in the presence of alcohols: influence on Ti incorporation and catalytic activity

Abstract

TS-1 has been synthesized following various recipes of the literature in the presence of alcohols, i.e., from gels that were not evaporated prior to crystallization, which considerably reduces the preparation time of the zeolites. When samples are prepared following a method adapted from the original patent, extra-framework species are observed even for low Ti contents. In contrast, when hydrolysis of the Si and Ti sources is performed in the presence of isopropyl alcohol, all Ti in the zeolite is incorporated in the lattice. However, incorporation is limited to about 1.9 Ti/u.c., even when catalysts are crystallized from gels with relatively high Ti concentrations. These samples are active in the hydroxylation of phenol with H₂O₂ and their activity is comparable with that of conventional catalysts obtained from alcohol-free gels.