Selective oxidation of benzyl alcohol to benzaldehyde with hydrogen peroxide over alkali-treated ZSM-5 zeolite catalysts

Hierarchical Zeolites and their Catalytic Performance in Selective Oxidative Processes

“…[31] The development of mesoporosity in hierarchical zeolites can open up the porous framework in these materials, and induce the formation of a large number of accessible terminal AlÀOH groups. [3] Liu et al [32] recently reported the catalytic performance of alkali-treated ZSM-5 zeolite in the selective oxidation of benzylalcohol with hydrogen peroxide, pointing out that the reaction mechanism involves the formation of AlÀ OOH groups by direct reaction of AlÀOH sites with H 2 O 2 . We recently reported the synthesis and characterization of iron oxide-functionalized hierarchical ZSM-5 zeolites with different Si/Al ratios.…”

“…Terminal and highly accessible AlÀOH groups can react with H 2 O 2 to generate highly reactive aluminum hydroperoxide surface species, which can then oxidize benzyl alcohol to benzaldehyde. [32,36] Table 1. Chemical composition, textural parameters, and surface properties of hierarchical zeolites used in this work.…”

“…This mechanism has already been proposed for homogeneous [36a] and heterogeneous alumina-based catalysts [36b-d] as well as for alkali-treated ZSM-5 zeolites. [32] Importantly, the proposed mechanism involves subsequent dehydration steps, which can be favored in acidic zeolite-type materials.…”

“…[33, 35b] This in turn may be due to the combination of the Fenton process (Fe 3 + + H 2 O 2 !Fe 2 + + H + + HOO·) [37] and the generation of highly reactive AlÀOOH surface species. [32,37] Zeolites beta and Y were previously reported as active catalysts in the selective oxidation of alkanes [38] and alkenes, such as cyclooctene conversion.…”

Synthesis, characterization and catalytic activity of polymer anchored transition metal complexes toward oxidation reactions

“…Therefore, heterogenizing of a homogeneous metal complex by supporting it on an insoluble support has attracted a lot of interest as a suitable method for solving many practical problems including recovery of the catalyst from reaction mixture and recycling. Transition metals supported on materials such as alumina [8], amorphous silicates [9], polymers [10] and zeolites [11] are commonly employed in heterogeneous catalysis.…”