3615-56-3Relevant articles and documents
Few-Unit-Cell MFI Zeolite Synthesized using a Simple Di-quaternary Ammonium Structure-Directing Agent
Abeykoon, Milinda,Al-Thabaiti, Shaeel,Bell, Alexis T.,Boscoboinik, J. Anibal,Dai, Heng,Dauenhauer, Paul,Dorneles de Mello, Matheus,Duan, Xuekui,Ghosh, Supriya,Kamaluddin, Huda Sharbini,Khan, Zaheer,Kumar, Gaurav,Li, Xinyu,Lu, Peng,Luo, Tianyi,Mkhoyan, K. Andre,Narasimharao, Katabathini,Qi, Liang,Rimer, Jeffrey D.,Tsapatsis, Michael
supporting information, p. 19214 - 19221 (2021/08/09)
Synthesis of a pentasil-type zeolite with ultra-small few-unit-cell crystalline domains, which we call FDP (few-unit-cell crystalline domain pentasil), is reported. FDP is made using bis-1,5(tributyl ammonium) pentamethylene cations as structure directing agent (SDA). This di-quaternary ammonium SDA combines butyl ammonium, in place of the one commonly used for MFI synthesis, propyl ammonium, and a five-carbon nitrogen-connecting chain, in place of the six-carbon connecting chain SDAs that are known to fit well within the MFI pores. X-ray diffraction analysis and electron microscopy imaging of FDP indicate ca. 10 nm crystalline domains organized in hierarchical micro-/meso-porous aggregates exhibiting mesoscopic order with an aggregate particle size up to ca. 5 μm. Al and Sn can be incorporated into the FDP zeolite framework to produce active and selective methanol-to-hydrocarbon and glucose isomerization catalysts, respectively.
Characterization of alditol oxidase from Streptomyces coelicolor and its application in the production of rare sugars
Chen, Zhou,Gao, Xiao-Dong,Li, Fen,Li, Zijie,Wang, Ning
, (2020/04/10)
A synthetic platform for the cascade synthesis of rare sugars using Escherichia coli whole cells was established. In the cascade, the donor substrate dihydroxyacetone phosphate (DHAP) was generated from glycerol by glycerol kinase (GK) and glycerol phosphate oxidase (GPO). The acceptor D-glyceraldehyde was directly produced from glycerol by an alditol oxidase. Then, the aldol reaction between DHAP and D-glyceraldehyde was performed by L-rhamnulose-1-phosphate aldolase (RhaD) to generate the corresponding sugar-1-phosphate. Finally, the phosphate group was removed by fructose-1-phosphatase (YqaB) to obtain the rare sugars D-sorbose and D-psicose. To accomplish this goal, the alditol oxidase from Streptomyces coelicolor (AldOS.coe) was expressed in E. coli and the purified AldOS.coe was characterized. Furthermore, a recombinant E. coli strain overexpressing six enzymes including AldOS.coe was constructed. Under the optimized conditions, it produced 7.9 g/L of D-sorbose and D-psicose with a total conversion rate of 17.7% from glycerol. This study provides a useful and cost-effective method for the synthesis of rare sugars.
Bi-Functional Magnesium Silicate Catalyzed Glucose and Furfural Transformations to Renewable Chemicals
Kumar, Abhinav,Srivastava, Rajendra
, p. 4807 - 4816 (2020/08/24)
Bio-refinery is attracting significant interest to produce a wide range of renewable chemicals and fuels from biomass that are alternative to fossil fuel derived petrochemicals. Similar to petrochemical industries, bio-refinery also depends on solid zeolite catalysts. Acid-base catalysis plays pivotal role in producing a wide range of chemicals from biomass. Herein, the Mg framework substituted MTW zeolite is synthesized and explored in the valorisation of glucose and furfural. Bi-functional (acidic and basic) characteristics are confirmed using pyridine adsorbed FT?IR analysis and NH3 and CO2 temperature-programmed desorption techniques. Textural properties and morphological information are retrieved from N2-sorption, X-ray photoelectron spectroscopy, and electron microscopy. The activity of the catalyst is demonstrated in the selective isomerisation of glucose to fructose in ethanol. Glucose is converted to methyl lactate in high yield using the same catalyst. Further, the bi-functional activity of this catalyst is demonstrated in the production of fuel precursor by the reaction of furfural and isopropanol. Mg?MTW zeolite exhibits excellent activity in the production of all these chemicals and fuel derivative. The catalyst exhibits no significant loss in the activity even after five recycles. One simple catalyst affording three renewable synthetic intermediates from glucose and furfural will attract significant attention to catalysis researchers and industrialists.
