Nickel porphyrin hybrid material based on functionalised silica for the selective oxidation of benzyl alcohol

Metalloporhyrin ligand,[tetrakis(o-chlorophenyl)porphyrinato]Ni(II) was successfully immobilised onto inorganic silica support from rice husk ash via 3-aminoprorplytriethoxysilane (APTES) and the resulting catalyst was labeled RHAC-NiPor. This mesoporous organic-inorganic hybrid catalyst showed a high specific surface area of 190.0 m2 g-1. The 29Si MAS NMR solid-state spectrum showed the presence of Q4,Q3,T3 and T2 silicon centres in RHAC-NiPor. The catalyst exhibited a good catalytic activity when used as a catalyst for the oxidation of benzyl alcohol with H2O2. A high selectivity to the desired product (benzaldehyde) of 100% and a maximum benzyl alcohol conversion of 54.9% was achieved. RHAC-NiPor could be reused several times without losing its catalytic activity. © Penerbit Universiti Sains Malaysia,2013.