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The hydroisomerization of n-alkanes is an important step in the production of high-quality bio-aviation kerosene. A SAPO-11 molecular sieve was synthesized using the hydrothermal synthesis method, and a 0.5 wt% Pt/SAPO-11 catalyst was prepared using the impregnation method. The crystal phase, pore structure, acidity, and morphology of Pt/SAPO-11 were characterized via X-ray diffraction, N2 adsorption-desorption, NH3 temperature-programmed desorption, scanning electron microscopy, and transmission electron microscopy, respectively. The hydroisomerization performance of the catalyst was evaluated with bio-n-hexadecane as the model compound. The results showed that temperature and space velocity had significant effects. Under the conditions of 340 °C, 1.5 MPa, WHSV = 1.0 h−1, V(H2): V(n-hexadecane) = 1000:1, the conversion of n-hexadecane and the selectivity of i-hexadecane were 81.8% and 86.5%, respectively. [ABSTRACT FROM AUTHOR]

The oxidative cleavage of vegetable oils and their derivatives to produce bio-based aldehydes is a potentially useful process, although the aldehyde products are readily oxidized to carboxylic acids and thus seldom obtained in high yields. The present study developed a room-temperature method for the synthesis of bio-aldehydes via the oxidative cleavage of vegetable oil-derived epoxides, using H 2 WO 4 as the catalyst, H 2 O 2 as the oxidant, and t -BuOH as the solvent. Reactions were carried out at temperatures ranging from 25 to 35 °C for 3.5-10.5 h, and provided >99% conversion and >90% aldehyde yield. In particular, an approximately 97% yield was obtained at 25 °C after 10.5 h. As the reaction proceeded, the H 2 WO 4 dissolved to form a W-containing anion. Several mesoporous Al-MCM-41 materials having different Si/Al ratios were hydrothermally synthesized and used as adsorbents to recover the catalyst by adsorbing these anions. The adsorption capacity of the Al-MCM-41 was found to increase with decreases in the Si/Al ratio. The Al-MCM-41 had little effect on the oxidative cleavage reaction at 25 °C, and thus could be directly added to the reaction system. The excellent anion adsorption performance of the Al-MCM-41 greatly improved the reusability of the H 2 WO 4 catalyst. When using the Al-MCM-41 with the best adsorption performance, there was no significant decrease in the activity of the catalyst following five reuses., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)