No abstract

No abstract

No abstract

A novel amino siloxane-functionalized MCM-41 supported Wells–Dawson type H6P2W18O62 (D-HPW) catalyst was synthesized by a two-step method and investigated in the gas phase dehydration of glycerol to acrolein, and the yield of acrolein was obviously improved.

Prompted by the scant attention paid by published literature reviews to the comprehensive catalytic dehydrogenative aromatization of cyclohexa(e)nones, this review describes recent methods developed to-date involving transition-metal-catalyzed oxidative aromatization and metal-free strategies for the transformation of cyclohexa(e)nones to substituted phenols.

No abstract

No abstract

The gas-phase dehydration of aqueous glycerol to acrolein was investigated using phosphorus-containing MCM-41 (HP-MCM-41) mesoporous molecular sieves, which were prepared via impregnation of phosphoric acid on the MCM-41. The catalysts were characterized by XRD, nitrogen adsorption-desorption, FTIR, NH 3 -TPD, and pyridine-FTIR measurements. Nitrogen adsorption studies suggested that the uniform framework of MCM-41 remained unchanged even after grafting phosphorus species on its surface. NH 3 -TPD analysis confirmed that moderate acidic sites had a positive effect on the formation of acrolein. Pyridine-FTIR results indicated that MCM-41 with grafted phosphorus species can noticeably enhance the percentage of Brønsted acid sites. Moreover, Brønsted acid sites facilitated the production acrolein selectively confirmed by catalytic results. The effects of H 3 PO 4 loading, calcination temperature, reaction temperature, and glycerol concentrations were also examined. The optimized 25HP-MCM-41 catalyst showed an 84 % selectivity of acrolein with glycerol conversion of 97 % at 320 8C.