Single-step preparation of zinco- and aluminosilicate delaminated MWW layers for the catalytic conversion of glucose

Abstract

Two-dimensional (2D) molecular sieves with highly dispersed active centers have great potential as catalysts for the transformation of bulky biomass derivatives owing to the ease of molecular diffusion and the...

Interzeolite Transformation of Borosilicate MWW to Metallosilicate BEA-Type Zeolites: Separated Kinetics of Structural Transformation and Metal Substitution

“…Co and Ni 2p XPS spectra have the peaks of shake-up satellites centered at 786.8 and 804.6 eV for Co and 862.0 and 880.0 eV for Ni. − The Me 2p 3/2 XPS spectra can be deconvoluted into two or three peaks. While the peaks that appeared at the lowest binding energy for Co- and Zn-BEA can be ascribed to the oxidized Co and Zn species, − almost no NiO moiety was observed in Ni-BEA. − However, both the Me 2p 3/2 peaks that appeared at the highest and the second highest binding energies of Me-BEAs should come from the framework metal species, − and these two deconvoluted bands can be assigned to the isolated and intermediate framework metal species, respectively, because the higher binding energy indicates the stronger interaction with the framework oxygen atoms. Additionally, the proportions of the two or three XPS peaks that appeared at high to low binding energy are comparable to those of their UV absorption bands at low to high wavelengths (Table S1).…”

“…For comparison, aluminosilicate (Al-MWW­(P), Si/Al = 15) and gallosilicate MWW precursors (Ga-MWW­(P), Si/Ga = 10) were also synthesized with a similar procedure of B-MWW­(P) using sodium aluminate (99%, Kanto) and gallium nitrate (100%, Strem), respectively, instead of boric acid (99.5%, Junsei). , The synthetic molar compositions of B-, Al-, and Ga-MWW­(P) were 2.0HMI·0.6Na 2 O·1.0B 2 O 3 ·3.0SiO 2 ·57H 2 O, 15HMI·1.7Na 2 O·1.0A 2 O 3 ·30SiO 2 ·1350H 2 O, and 10HMI·2.0Na 2 O·1.0Ga 2 O 3 ·20SiO 2 ·900H 2 O, respectively. Metallosilicate Me-MWWs (Me = Co, Ni, and Zn) were prepared by hydrothermal treatment of B-MWW­(P) with 1 M cobalt­(II) nitrate hexahydrate (98%, Junsei), nickel­(II) nitrate hexahydrate (98%, Samchun), and zinc­(II) nitrate hexahydrate (98%, Samchun) solutions, respectively, following the procedures reported in our previous works. , The synthetic molar composition of Me-MWW was 4.0SiO 2 ·1.0MeO·9.4H 2 O. All of the as-synthesized MWWs were calcined at 550 °C for 8 h to remove the occluded organic SDA.…”

“…41,42 The synthetic molar compositions of B-, Al-, and Ga-MWW(P) were 2.0HMI•0.6Na B-MWW(P) with 1 M cobalt(II) nitrate hexahydrate (98%, Junsei), nickel(II) nitrate hexahydrate (98%, Samchun), and zinc(II) nitrate hexahydrate (98%, Samchun) solutions, respectively, following the procedures reported in our previous works. 43,44 The synthetic molar composition of Me-MWW was 4.0SiO 2 •1.0MeO•9.4H 2 O. All of the as-synthesized MWWs were calcined at 550 °C for 8 h to remove the occluded organic SDA.…”

“…This catalytic reaction is well known: glucose is converted to fructose by the isomerization at the Lewis acid site, and 5-HMF is formed consecutively by the dehydration of fructose at the Brønsted acid site. 44 5-HMF can be used as a raw material to produce biomass-derived poly(ethylene furandicarboxylate) (PEF) that can replace poly(ethylene terephthalate) (PET). Figure 5c shows glucose conversion over fully interconverted Co-, Ni-, and Zn-BEA.…”

Facile synthesis of SAPO-34 nanocrystallites with excellent performance for the dehydration of carbohydrates to 5-hydroxymethylfurfural

“…This process is plagued by issues such as equipment corrosion and waste treatment. 14 Owing to the recoverability and low corrosivity of heterogeneous acid catalysts, significant efforts have been made to explore their catalytic application for 5-HMF production, including ion exchange resins, 15 metal oxides, 16 heteropoly acids, 17 graphene oxide, 18 aluminosilicate molecular sieves, [19][20][21][22] and silicoaluminophosphate (SAPO) molecular sieves. Among them, SAPO molecular sieves stand out for their ultra-high (hydro)thermal stability, original porosity, tunable acidity, and hydrophilicity.…”