Relevant articles and documents
Mesoporous tantalum phosphates: Preparation, acidity and catalytic performance for xylose dehydration to produce furfural
Xing, Yanran Yan, Bo Yuan, Zifei Sun, Keqiang
Mesoporous tantalum phosphates (TaOPO4-m) with varying P/Ta molar ratios (m = 0.41-0.89) were prepared, comprehensively characterized by ICP-AES, N2 physisorption, small-angle XRD, TEM, Raman, FT-IR, NH3-TPD and IR of pyridine adsorption and employed to catalyze the dehydration of xylose to produce furfural in a biphasic batch reactor. The physicochemical properties of these TaOPO4-m samples were affected significantly by variation of m. More ordered mesopores were formed in the sample with a higher m. On the other hand, the density of acidity decreased but the ratio of Br?nsted acidity to Lewis acidity (B/L) increased with the increase in m. TaOPO4-0.84, which showed adequate mesoporosity and a high B/L ratio, was identified as the best performing catalyst among these TaOPO4-m catalysts in terms of high furfural selectivity (ca. 72 mol%). Correlating the catalyst performance with its acid property showed that the xylose consumption rate decreased with the increasing B/L ratio, while furfural selectivity showed a volcano-type dependence on the B/L ratio. Besides, the huge decrease in the furfural selectivity after poisoning the Br?nsted acid sites by adding 2,6-dimethyl pyridine revealed a kind of Br?nsted acid catalysis for selective furfural production.
Dehydration of xylose over sulfated tin oxide catalyst: Influences of the preparation conditions on the structural properties and catalytic performance
Suzuki, Takeshi Yokoi, Toshiyuki Otomo, Ryoichi Kondo, Junko N. Tatsumi, Takashi
Various sulfated metal oxides were tested as solid acid catalyst for the dehydration of xylose to furfural under milder conditions. On the basis of our findings that sulfated tin oxide exhibited the highest catalytic activity, the effects of the content of SO42- group and the calcination temperature on the structural properties and catalytic performance were investigated, and the reusability of the sulfated tin oxide catalyst was evaluated. The acid property on the sulfated tin oxide catalyst was characterized by in situ FT-IR observations of the CO-adsorbed sample. Finally, the reaction mechanism of dehydration of xylose over the SO4 2-/SnO2 catalyst was considered.







