Spongy titanosilicate promotes the catalytic performance and reusability of WO(3) in oxidative cleavage of methyl oleate

A tungsten containing catalyst catalyzed oxidative cleavage of methyl oleate (MO) by employing H(2)O(2) as an oxidant and is known as an efficient approach for preparing high value-added chemicals, however, the tungsten leaching problem remains unresolved. In this work, a binary catalyst consisting of tungsten oxide (WO(3)) and spongy titanosilicate (STS) zeolite is proposed for MO oxidative cleavage. The function of STS in this catalyst is investigated. On the one hand, STS converts MO to 9,10-epoxystearate (MES), which further forms nonyl aldehyde (NA) and methyl azelaaldehydate (MAA) with the catalysis of WO(3). In this way, MO oxidation and hydrolysis that generates unwanted diol product 9,10-dihydroxystearate (MDS) decreases obviously. On the other hand, STS decomposes peroxide and promotes the conversion of soluble peroxotungstate to insoluble polytungstate. Meanwhile, these tungsten species are allowed to precipitate on its surface instead of remaining in the liquid phase owing to its relative large specific area. Therefore, tungsten leaching can be reduced from 37.0% to 1.2%. Due to the cooperation of WO(3) and STS, 94.4% MO conversion and oxidative cleavage product selectivity of 63.1% are achieved, and the WO(3)–STS binary catalyst maintains excellent catalytic performance for 8 recycling reactions.