Selective tandem catalysis for the synthesis of 5-hydroxymethylfurfural from glucose over in-situ phosphated titania catalysts: Insights into structure, bi-functionality and performance in flow microreactors

Titanium Phosphate Grafted on Mesoporous SBA-15 Silica as a Solid Acid Catalyst for the Synthesis of 5-Hydroxymethylfurfural from Glucose

“…The adsorbances at 1540 and 1635 cm −1 are assigned to pyridine protonated on BAS, the adsorbances at 1446 and 1606 cm −1 are attributed to pyridine adsorbed on LAS, and the band at 1489 cm −1 is from pyridine on both LAS and BAS. 12 In line with the literature, 42,43 anatase TiO 2 exhibited only Lewis acidity, which decreased largely upon phosphation (PO 4 3− /TiO 2 ), together with the appearance of little amount of BAS. Comparatively, titania and titanium phosphate layers on SBA-15 exhibited a much higher amount of both LAS and BAS.…”

“…20 wt % NaCl was added in water to promote the HMF extraction into mTHF (e.g., the partition coefficient of HMF at 150 °C Adapted from our previous work. 12 increases from 1.01 to 2.17 after adding 20 wt % NaCl 12 ). The reactions were performed at an optimized temperature of 160 °C with 0.1 M glucose (cf.…”

“…12,41 Generally, the titania layer grafted on SBA-15 (nTi/SBA-15) affords a significantly higher acidity than bulk anatase (TiO 2 ), so does the corresponding titanium phosphate layer (P-nTi/SBA-15) compared with PO 4 3− /TiO 2 . This is well consistent with (i) the by far larger portion of the unsaturated tetrahedral Ti ions (and thus the amount of LAS 12 ) on nTi/SBA-15 and P-nTi/ SBA-15 than that on bulk TiO 2 and PO 4 3-/TiO 2 (Figure 5); (ii) the much larger loading of phosphate (and thus the amount of BAS) on P-nTi/SBA-15 than PO 4 3− /TiO 2 (Table 1); as well as (iii) the much higher surface area of the SBA-15supported samples (Table 1). The overall acidity of both nTi/ SBA-15 and P-nTi/SBA-15 was observed to increase, despite the decreased surface area (Table 1), with the increasing grafting cycles up to three according to NH 3 -TPD results.…”

Microflow chemistry and its electrification for sustainable chemical manufacturing

“…131,153 Glucose: batch single-phase reaction, 141,145,168,169 batch biphasic reactions,135,140,144-146 and continuous biphasic reactions. 153,154…”

Efficient synthesis of furfural from xylose over HCl catalyst in slug flow microreactors promoted by NaCl addition

“…Batch reactors often suffer from a poor control over flow pattern, heat/mass transfer when scaled up, which tends to limit the xylose conversion efficiency in the aqueous phase and furfural extraction to the organic phase leading to low furfural yields. Recently, microreactors have been used as a promising tool for kinetic study and production platform for HMF synthesis from C 6 sugars in monophasic or biphasic solvent systems, [15][16][17][18][19][20] due to advantages such as the superior heat/ mass-transfer efficiency, precise process control, continuous operation mode, the ease of production capacity increase, and thus holding great promises for improving process sustainability and circularity. 21,22 Comparatively, few reports have been published on its application for furfural synthesis.…”