Liu Kande,Wang Sitan,Zheng Lishan,Lou Shifeng,Meng Xuan,Cao Fahai,Liu Naiwang,Shi Li
The catalytic performance of Hβ zeolite treated with different concentration of NaOH on the alkylation of tert-butanol with phenol was studied. The effect of NaOH concentration on the crystallinity, morphology, textural property and acidity of Hβ zeolite was studied by X-ray diffraction (XRD), scanning electron microscope characterization (SEM), N 2 adsorption–desorption, Fourier transform infrared spectroscopy (FT-IR) and pyridine adsorption infrared spectra (Py-IR) techniques. A certain concentration of NaOH treatment can regulate the pore structure of Hβ zeolite and remove part of framework aluminum and framework silicon, thus achieving the purpose of regulating the pore structure and acidity of the catalyst. Though lower Bronsted to Lewis acid amount ratio when treated NaOH concentrations were 0.15 mol/L, leading to the increasing of selectivity to 4-TBP. The Hβ-0.2 M showed the high selectivity of 90.21% for synthesis of 4-tert-butyl-phenol (4-TBP), compared with the unmodified parent zeolite, the selectivity of 4-TBP improved 16.7%. Graphical Abstract
Yuxi Wang,Yong Yu,Shuhan Hu,Jinyao Yu,Yue Huang,Hongjie Dai
Pineapple peel cellulose nanofibrils (PCNFs) were facilely prepared by the ball milling method assisted by alkali solution (3 wt% NaOH) and a wet grinding medium, using various treated pineapple peels (hot water treatment (WT), bleaching treatment (BT), alkaline treatment (AT), and baleaching–alkaline treatment (ABT)) as raw materials. The structure of the obtained PCNFs (i.e., WT-PCNF, BT-PCNF, AT-PCNF, and ABT-PCNF) was characterized to analyze the influence of component intervention. The results indicated that NaOH-assisted ball milling did not change the crystal structure of cellulose, and the yield and thermal stability of the PCNFs was improved. The average diameters of WT-PCNF, BT-PCNF, AT-PCNF, and ABT-PCNF were 24.16, 21.53, 23.04, and 19.46 nm, respectively, in which BT-PCNF and ABT-PCNF exhibited a higher defibrillating degree and smaller diameter. Particularly, NaOH-assisted ball milling can promote the removal of non-cellulose components. The viscosity and modulus of BT-PCNF were relatively higher due to the presence of residual hemicellulose as a natural linker of fibers. The current research provides insights for simplifying the preparation and functionalization of nanocellulose.
危险品化学品经营许可证（带存储）