Metathesis of 1-octene over MoO3 supported on mesoporous molecular sieves: The influence of the support architecture

New types of heterogeneous catalysts for alkene metathesis based on molybdenum oxide supported on mesoporous molecular sieves MCM-41, MCM-48 and SBA-15 were developed. These new systems represent inexpensive, easy-to-prepare and highly active and selective heterogeneous catalysts for metathesis of linear alkenes applicable under mild reaction conditions without the necessity of solvent or co-catalyst presence in the reaction mixture. In metathesis of 1-octene, these catalysts showed considerably higher activity compared with MoO3 supported on conventional silica with selectivity to 7-tetradecene being in the range between 60% and 95%. The highest activity exhibited MoO3/MCM-41 with 6 wt.% of Mo (75% conversion after 6 h at 40 °C with selectivity to 7-tetradecene 84%). The turn-over-frequency of the catalysts loaded with 8 wt.% of Mo decreased in the order MCM-41 > MCM-48 > SBA-15, while the selectivity slightly increased in the same order. Using Raman spectroscopy, the differences in the catalytic activity were elucidated as a result of different dispersion of the active phase over the supports.