Abstract: Pd nanoparticles were successfully captured by tetraimine groups incorporated into the channel of periodic mesoporous organosilica (PMO-SBA-15), yielding a Pd-containing mesoporous organosilica catalyst (Pd/PMO-SBA-15). N₂ adsorption-desorption, X-ray diffraction, and transmission electron microscopy confirmed that the Pd nanoparticles were well stabilized and dispersed uniformly inside the channel of the PMO with average particle size of 1.8 nm. The Pd/PMO-SBA-15 was used as a catalyst for selective oxidation of benzyl alcohol with H₂O₂ as oxidant in water. The effects of various nanoparticles, H₂O₂ amount, reaction temperature, and reaction time on the oxidation were investigated. The benzyl alcohol conversion of 97.1% with the selectivity for benzaldehyde of 100.0% was obtained when the reaction was carried out in water with 0.05 g of 2%Pd/PMO-SBA-15 and 1.5 ml of H₂O₂ at 80 ^oC for 4 h. Furthermore, the Pd/PMO-SBA-15 could be conveniently recovered for recycle use. The conversion of benzyl alcohol decreased with the increase of reuse times.

Key words: palladium, nanoparticle, periodic mesoporous organosilica, selective oxidation, benzyl alcohol, benzaldehyde