Herein
we report on the catalytic activity of mesoporous nickel, iron, cerium,
cobalt, and manganese oxides prepared using KIT-6 as a hard template
via evaporation-assisted precipitation. The mesoporous metal oxides
(MMOs) were characterized and used as heterogeneous catalysts in the
reduction of 4-nitrophenol (4-Nip) by sodium borohydride (BH4
–). Furthermore,
polyamidoamide (PAMAM) dendrimers were used to synthesize gold–palladium
nanoalloy particles. The size of AuPd/PAMAM was found to be 3.5 ±
0.8 nm in diameter before being immobilized on the aforementioned
mesoporous metal oxides and used as catalysts in the reduction of
4-Nip. Prior to catalytic evaluation, the reduction profiles of the
mesoporous metal oxides were investigated by hydrogen-temperature-programmed
reduction (H2-TPR) and showed that mesoporous metal oxides
can be easily reduced at lower temperatures and that the immobilization
of gold–palladium nanoalloy particles lowers their reduction
temperatures. Mesoporous cobalt and manganese oxides showed catalytic
activity toward 4-Nip reduction, and the activity was enhanced after
immobilization of the gold–palladium nanoalloys. Isolation
of nanoparticles activity was achieved by immobilization of the gold–palladium
nanoalloys on the inert silica support. From this we postulated an
electron relay mechanism for the reduction of 4-nitrophenol. With
the use of power rate law we showed that 4-Nip reduction follows pseudo-first-order
kinetics.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.