Effective SO4 2−/TiO2–ZrO2 for preparation and hydrolysis of 1,3-propanediol acetals

Abstract

SO 4 2-/TiO 2 -M x O y (M = Zr, Ce, La) were prepared by the precipitation-impregnation method and characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR), and temperature-programmed desorption (NH 3 -TPD). Catalytic activities were evaluated in the acetalization of 1,3-propanediol (1,3-PD) with acetaldehyde and hydrolysis of 2-methyl-1,3-dioxane (2MD). SO 4 2-/ TiO 2 -ZrO 2 (STZ) exhibited the best catalytic activity both in the acetalization and hydrolysis. With the molar ratio of Zr 4? /Ti 4? = 1:4, the highest yields were 96.45% in 3 h and 93.68% of 2MD hydrolyzed in 18 h, in contrast to the yields lower than 60% by using other superacids. These results are consistent with the strongest acidity of the superacid containing Zr 4? among prepared superacids containing other cations.

ZrO2–MoO3 for the Acetalization of 1,3-Propanediol from Dilute Solutions

“…A relatively well-developed approach is the acetalization of 1,3-PD to form highly hydrophobic acetals (2-methyl-1,3-dioxane, 2MD), followed by hydrolysis to 1,3-PD (Scheme ). This cyclic reaction has been reported previously. , …”

Sulfated Ce‐doped TiO2 as visible light driven photocatalyst: Preparation, characterization and promotion effects of Ce doping and sulfation on catalyst performance

“…For SCT 0.03 −1.5 and ST‐1.5, besides TiO 2 characteristics, the infrared bands at around 1060, 1120 and 1215 cm −1 are assigned to the characteristic frequencies of a bidentate coordinated to metals. Such a structure is capable of withdrawing electrons from the neighboring metal cations (Ti 4+ ), resulting in an increase in electron‐deficiency on these cations that could then act as Lewis acid sites . This mechanism is believed to be the source in the generation of increased surface acidic sites on the sulfated samples.…”