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Pd-Re/SBA-15 catalysts with different Pd precursors were prepared by the impregnation method. N 2 adsorption-desorption, XRD, H 2 -TPR, TEM and NH 3 -TPD were used to characterize the physical and chemical properties of the catalysts. Pd-Re catalysts with different precursors showed different activities in the reaction of glycerol hydrogenolysis. 5Pd-5Re/SBA-15 with PdCl 2 as Pd precursor had higher activity than those with Pd(NO 3 ) 2 and Pd(OAc) 2 as precursors. The existence of Cl could affect the particle sizes, reduction behaviors and the acid properties of Pd-Re catalysts. [ABSTRACT FROM AUTHOR]

The synthesis of glycerol carbonylation with CO 2 to glycerol carbonate over CeO 2 catalyst was investigated. CeO 2 with different morphologies was prepared by traditional precipitation (TP), hydrothermal (TH) and citrate sol-gel (SG) methods, and the reaction of glycerol with CO 2 was carried out in the presence of a dehydrating agent and solvent. The effect of preparation methods of CeO 2 and reaction parameters on the activity and selectivity of the catalysts were examined. The structures, morphologies and surface properties of the catalysts were characterized by XRD, TEM, BET, CO 2 -TPD, H 2 -TPR, Raman and XPS. CeO 2 exhibited high catalytic activity for the formation of glycerol carbonate under mild reaction conditions. The carbonylation of glycerol was influenced by the redox property of CeO 2 . The effects of different types of dehydrating agent and solvent were also studied. The dehydrating agent (2-cyanopyridine) and solvent (Dimethyl Formamide(DMF)) contributed to the increase of glycerol conversion and the yield of glycerol carbonate. The yield of glycerol carbonate could reach as high as 78.9%, and the catalysts could be easily regenerated by calcination at 400 °C for 5 h without loss of activity after 5 recycling times. The proper reaction conditions were 150 °C, 4 MPa and 5 h. [ABSTRACT FROM AUTHOR]

Highlights: [•] ·Ru catalysts with HZSM5(X) were used during glycerol hydrogenolysis. [•] ·As the acid amount increased, the glycerol conversion and CH4 selectivity increased. [•] ·The acid amount and acid strength of HZSM5(X) affected the C C bond cleavage. [•] ·Loading Ru on HZSM5(X) could modulate the acidity and decrease CH4 selectivity. [ABSTRACT FROM AUTHOR]

Abstract: RhCl3 was immobilized to diphenylphosphinopropyl (–PrPPh2)-modified mesoporous silica SBA-15 through a multi-step-assembly process. The prepared catalyst was characterized with reference to bulky and surface properties by X-ray diffraction (XRD), infrared spectroscopy (FT-IR), isothermal nitrogen sorption analysis and X-ray photoelectron spectroscopy (XPS). The metal content was determined by inductive coupling plasma-atomic emission spectroscopy (ICP-AES). The prepared rhodium-immobilized catalyst was employed in hydroformylation of several higher olefins of different lengths (C6, C8, and C10), different Csitions (terminal or internal) or different structures (linear or branched). The substrate influences on the activity and recycling stability of the immobilized catalyst were investigated and are discussed. Shorter linear olefin substrates were more easily activated with higher catalyst specific activity, while the catalyst showed recycling stability in hydroformylation of longer and branched olefin substrates. For comparison, PPh3 was externally added to immobilize RhCl3 to –PrPPh2-modified SBA-15. The immobilized catalyst so prepared showed a more flexible immobilizing structure and revealed a promoted turnover number of substrates. [Copyright &y& Elsevier]