Identification of the most active sites for tetrahydropyranylation in zeolites: MFI as a test case

Selective Recovery and Recycling of Germanium for the Design of Sustainable Zeolite Catalysts

“…The catalytic performance of post-synthesized IWW /Me post zeolites was tested in model reactions, such as (1) THP of 1-hexanol with 3,4-dihydro-2 H -pyran (Scheme a), which is known to be catalyzed by Brønsted acid sites, (2) epoxidation of 1-octene (Scheme b) efficiently catalyzed by Ti Lewis acid sites, and (3) BVO of cyclohexanone with hydrogen peroxide (Scheme c) proceeding on Sn Lewis acid centers …”

“…Catalytic Behavior of Al-, Ti-, Sn-Substituted IWW Zeolites. The catalytic performance of post-synthesized IWW/Me post zeolites was tested in model reactions, such as (1) THP of 1-hexanol with 3,4-dihydro-2H-pyran (Scheme 4a), which is known to be catalyzed by Brønsted acid sites, 44 (2) epoxidation of 1-octene (Scheme 4b) efficiently catalyzed by Ti Lewis acid sites, and (3) BVO of cyclohexanone with hydrogen peroxide (Scheme 4c) proceeding on Sn Lewis acid centers. 15 The activities of IWW/Me post were compared with those of hydrothermally synthesized Al-IWW hydro and of commercial TS-1 zeolites with close Si/Al and Si/Ti ratios, respectively (Table 3).…”

Correlating mesoporosity/acidity with catalytic performances for surfactant-templated mesoporous FAU zeolites

“…48–50 In addition, the diffusion of reactants in zeolite catalysts was reported as the rate-determining step. 50 Therefore, hierarchical zeolites with transport mesopores or macropores that facilitate the diffusion of reactants are considered the best candidates for the tetrahydropyranylation reaction. 50–52 In our study, only targeted tetrahydropyranyl ethers were detected as products ( i.e.…”

“…50 Therefore, hierarchical zeolites with transport mesopores or macropores that facilitate the diffusion of reactants are considered the best candidates for the tetrahydropyranylation reaction. 50–52 In our study, only targeted tetrahydropyranyl ethers were detected as products ( i.e. , selectivity >99%) in the O -alkylation of both alcohols over the investigated catalysts, initial CBV720 or hierarchical NaOH/Si- n .…”

“…According to the literature, both Brønsted and Lewis acid sites can catalyze this reaction, but strong BAS are more active than LAS. [48][49][50] In addition, the diffusion of reactants in zeolite catalysts was reported as the rate-determining step. 50 Therefore, hierarchical zeolites with transport mesopores or macropores that facilitate the diffusion of reactants are considered the best candidates for the tetrahydropyranylation reaction.…”