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

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 WO_x 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.