摘要：

The present work has been undertaken with an aim to synthesize valuable bio-additive fuels from glycerol acetalization using SnO2-based solid acids. Various promoters, namely SO42, MoO3and WO3were incorporated to the SnO2using a wet-impregnation method. An extensive physicochemical characterization has been achieved by means of XRD, BET surface area, BJH analysis, FT-IR, pyridine adsorbed FT-IR, NH3-TPD, ICP-OES and XPS techniques. The BET surface area of SnO2is significantly improved from 11 to 32, 56 and 41 m2g1after the addition of the WO3, MoO3, and SO42promoters, respectively. The XPS studies revealed that Sn is present in the +4 oxidation state, whereas Mo, W and S are in the +6 oxidation state in the prepared samples. In addition, the SO42/SnO2sample contained super acidic sites, along with strong- and medium-acidic sites. The amount of acidic sites was found to be 46.47, 61.81, 81.45 and 186.98 μmol g1for the SnO2, WO3/SnO2, MoO3/SnO2, and SO42/SnO2samples, respectively. The pyridine adsorbed FT-IR studies revealed the existence of a superior quantity of Brnsted acidic sites than Lewis acidic sites in the synthesized catalysts. Promoted SnO2catalysts exhibited a promising catalytic performance for glycerol acetalization with acetone and furfural, and the activity of the catalysts was found to increase in the following order: SnO2< WO3/SnO2< MoO3/SnO2< SO42/SnO2. The outstanding performance of the SO42/SnO2catalyst is mainly due to the existence of a large amount of acidic sites associated with the super acidic sites. The achieved optimum glycerol conversions with acetone and furfural were ~98 and 99% over the SO42/SnO2catalyst, respectively.

展开