Silica-Supported Boron Phosphate Catalyst Prepared by Chemical Vapor Deposition

Article abstract of DOI:10.1246/bcsj.64.516

A silica supported boron phosphate (BPO4) catalyst was prepared by chemical vapor deposition (CVD) using mixtures of boron triethoxide and phosphoryl trimethoxide.Both the amount and the P/B ratio of deposited BPO4 were changed with the CVD temperature and time.At the optimum CVD temperature of 300 deg C, the amount of deposited BPO4 was linearly increased with the CVD time.When alkoxide mixtures with the desired P/B ratio were used as CVD sources at 300 deg C, the expected P/B ratios were available.At CVD temperatures below 300 deg C, neither a sufficient amount nor a desired P/B ratio was given.On the other hand, above 325 deg C, the deposition was suppressed by blocking the micropore of silica, especially for long-time CVD operation, owing to the too fast deposition.Although the resulting surface compound was amorphous, it was revealed to have microstructures of BPO4 by means of a (31)P NMR measurement.The amorphous BPO4 dispersed highly on silica exhibited a high catalytic efficiency for the isomerisation of 1-butene and a simultaneous oligomerization of 1-butane in comparison with a catalyst prepared by the conventional impregnation method.