Tungsten-containing MCF silica as active and recyclable catalysts for liquid-phase oxidation of 1,3-butanediol to 4-hydroxy-2-butanone Original Research Article

W-containing mesocellular silica foams (MCF) having a Si/W (molar) ratio of 10–40 were synthesized and characterized by means of N2 adsorption, SAXS, XRD, TEM, DRIFTS, DR UV–vis and Raman spectroscopy. The results show that tungsten was well incorporated inside the MCF material and the nature of WOx species closely depends on the tungsten content. At low tungsten content (Si/W ≥ 20), the characteristic mesocellular structure of the MCF material was well maintained while at higher tungsten content (Si/W ∼ 10) a significant degradation of the mesocellular arrangement of MCF pores was observed. The selective liquid-phase oxidation of 1,3-butanediol (1,3-BDO) to 4-hydroxy-2-butanone (HB) over the W-MCF material with various Si/W ratios was investigated. Under optimized reaction conditions, the W-MCF catalyst showed a superior catalytic performance in the selective oxidation of 1,3-BDO as compared to other W-containing materials such as WO3/MCF and W-SBA-15. Moreover, a very stable catalytic activity as a function of cycling test was observed for the W-MCF catalyst.