Intimately interacting Pt–FeOxentities preparedviagalvanic displacement are highly selective for the chemoselective hydrogenation of the CO bond in cinnamaldehyde.

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Mesoporous tantalum phosphates (TaOPO 4 -m) with varying P/Ta molar ratios (m ¼ 0.41-0.89) were prepared, comprehensively characterized by ICP-AES, N 2 physisorption, small-angle XRD, TEM, Raman, FT-IR, NH 3 -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 TaOPO 4 -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 Brønsted acidity to Lewis acidity (B/L) increased with the increase in m. TaOPO 4 -0.84, which showed adequate mesoporosity and a high B/L ratio, was identified as the best performing catalyst among these TaOPO 4m 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 Brønsted acid sites by adding 2,6-dimethyl pyridine revealed a kind of Brønsted acid catalysis for selective furfural production. Fig. 7 Performance of the TaOPO 4 -m catalysts with different molar P/Ta ratio m by the time courses of (A) xylose conversion, (B) furfural selectivity: m ¼ 0.41 (-), m ¼ 0.61 (B), m ¼ 0.75 (:), m ¼ 0.84 (A), and m ¼ 0.89 (P).This journal is

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