Photocrosslinked styrene-butadiene-styrene block copolymer (SBS) membrane supported nano platinum catalysts was prepared and their catalytic activity on the selective hydrogenation of cinnamaldehyde was investigated. The platinum nanoclusters with an average diameter of ca 3.7 nm were obtained by reaction of H₂PtCl₆ with polyols, assisted by microwave irradiation (MW). The SBS membrane was loaded with 3.0 wt% of Pt, benzophenone (BP) and 1,1,1-trimethylolpropane triacrylate (TMPTA), respectively, and varing crosslinking ratios were achieved by adjusting the radiation time. The hydrogenation products were investigated by gas chromatography and mass spectrometry (GC-MS) and UV techniques. As the crosslinking ratio increases, the selectivity for cinnamyl alcohol first increases and reaches 80.98% at a crosslinking ratio of 23.63%, and then decreases. Decomposition products of the SBS meambrane itself begin to appear as the radiaton time is over 30 min (corresponding to a crossling ratio of slghtly above 30%). The deterioration of the membrane structure is also evidenced by transmission electron microscope (TEM) measurement.

Key words: cinnamaldehyde hydrogenation, membrane-supported platinum catalyst, photocrosslinking, styrene-butadiene-styrene block copolymer (SBS)