Catalytic conversion of glycerol to acrolein over MCM‐41 by the grafting of phosphorus species

Abstract

The gas-phase dehydration of aqueous glycerol to acrolein was investigated using phosphorus-containing MCM-41 (HP-MCM-41) mesoporous molecular sieves, which were prepared via impregnation of phosphoric acid on the MCM-41. The catalysts were characterized by XRD, nitrogen adsorption-desorption, FTIR, NH 3 -TPD, and pyridine-FTIR measurements. Nitrogen adsorption studies suggested that the uniform framework of MCM-41 remained unchanged even after grafting phosphorus species on its surface. NH 3 -TPD analysis confirmed that moderate acidic sites had a positive effect on the formation of acrolein. Pyridine-FTIR results indicated that MCM-41 with grafted phosphorus species can noticeably enhance the percentage of Brønsted acid sites. Moreover, Brønsted acid sites facilitated the production acrolein selectively confirmed by catalytic results. The effects of H 3 PO 4 loading, calcination temperature, reaction temperature, and glycerol concentrations were also examined. The optimized 25HP-MCM-41 catalyst showed an 84 % selectivity of acrolein with glycerol conversion of 97 % at 320 8C.

Porous Silicon-Based Catalysts for the Dehydration of Glycerol to High Value-Added Products

“…Another strategy to generate Brönsted acid sites on the surface of mesoporous MCM-41 silica was by impregnation with phosphoric acid and subsequent calcination [ 46 ]. This catalyst followed the same trend as that observed for the mesoporous silica functionalized with sulfonic acid groups, since the main product was acrolein ( Table 2 ) with a negligible amount of hydroxyacetone.…”

Gas phase dehydration of glycerol to acrolein over WO3-based catalysts prepared by non-hydrolytic sol–gel synthesis

“…Several type of catalysts have been proposed in the last years, 4–7 including zeolites, 9,10 heteropoly acids and acidic heteropoly salt, 11 phosphate-based materials 12 and oxides. 13–21 Among these, W-containing materials (both bulk and supported ones), 15–21 are promising catalysts due to their high selectivity to acrolein and catalyst stability.…”

Continuous Flow Upgrading of Selected C2–C6Platform Chemicals Derived from Biomass

“…Ma et al studied MCM-41 mesoporous molecular sieves that were impregnated with phosphoric acid. 288 H 3 PO 4 enhanced Brønsted acidity of the catalyst, and thus acrolein formation, but at too high concentration, it also altered the pore framework. Under optimized conditions, the conversion of glycerol was maintained at 92−94% and the selectivity toward acrolein at 84−82% for 12 h TOS, and then these values dropped to 76% and 57%, respectively, after 24 h TOS (Table 10, entry 6).…”