Synthesis and Structures of A Series of Novel Rare Earth Transition Metal Sulfates

Seven new rare earth transition metal sulfates were synthesized by hydrothermal reactions under conditions slightly above the critical point of water. Their crystal structures were determined from single crystal X-ray data. The compositions of the new compounds can be represented by two general formulae ： REM （OH） 3 （SO4） and RE2M （OH） 3 （SO4） 2F （H2O） with RE = Gd, Tb, Dy ; M = Ni, Cu. Three different crystal structure types were found for the formula REM （OH） 3 （SO4）. The structures of the new compounds all feature infinite chains of REOn coordination polyhedra, which are connected to chains of CuO6 or NiO6 octabedra. The limited size range of the rare earth cations observed in these compounds is most likely because of interactions between the octabedral chains and the chains of REOn polyhedra. The new compounds are closely related to the known yttrium transition metal sulfates.

Efficient one-pot synthesis of n-butyl levulinate from carbohydrates catalyzed by Fe_2(SO_4)_3

Butyl levulinate（BL） is a promising new candidate as diesel fuel and fuel additive. In this study, an efficient process for a one-pot synthesis of BL from biomass-derived carbohydrates in butanol medium with the catalysis of metal sulfates was developed. The catalytic activity of a series of metal sulfates for the synthesis of BL from fructose was investigated. Among various metal sulfates, ferric sulfate Fe（SO）was found to be the most efficient catalyst, which gave a remarkably high BL yield of 62.8 mol% under the conditions of 463 K, 3 h, a catalyst dosage of 5.0 g/L, and fructose concentration of 25 g/L. Different carbohydrates including glucose, cellulose, inulin and sucrose were also used for one-pot synthesis of BL with the catalysis of Fe（SO）, showing the yields of 39.6, 30.5, 56.6 and 50.1 mol%, respectively. In addition,the recycling and reuse of Fe（SO）was studied by characterizing them using powder X-ray diffraction（XRD）, scanning electron microscope（SEM）, X-ray photoelectron spectroscopy（XPS）. A plausible reaction pathway for the one-pot synthesis of BL from fructose was proposed. This study provides a facile and feasible way for the synthesis of BL from biomass.

Al(HSO_4)_3/silica gel as a novel catalytic system for the ring opening of epoxides with thiocyanate anion under solvent-free conditions

For the first time,metal hydrogen sulfates and phosphates/silica gel have been studied as efficient and powerful solid acid catalysts in the ring opening of epoxides with thiocyanate anion.The most significant result was obtained by Al(HSO4)3/SiO2which afforded the corresponding β-hydroxy thiocyanates under mild reaction conditions and in very short reaction times.The cheapness, availability of the catalyst,ease of procedure and work-up make this method attractive for the organic synthesis.

Mild hydrothermal preparation of a layered metal hydroxide salt with microtube/rod morphology

Microtubes/rods of the layered metal hydroxide salt compound Cd2（OH）3（DS）·nH2O, where DS stands for dodecyl sulfate sandwiched between two adjacent inorganic sheets, have been synthesized for the first time through a mild hydrothermal reaction route. The microtubes/rods have a diameter of about 1 μm and a length ranging from several microns to 20μm. The growth process of microtubes/rods under the experimental conditions employed follows a dissolution-recrystallization route.

Improvement of the activity and SO_(2) tolerance of Sb-modified Mn/PG catalysts for NH_(3)-SCR at a low temperature

A series of MnM/palygorskite(PG)(M=La,W,Mo,Sb,Mg)catalysts was prepared by the wetness co-impregnation method for low-temperature selective catalytic reduction(SCR)of NO with NH_3.Conversion efficiency followed the order Sb>Mo>La>W>Mg.A combination of various physico-chemical techniques was used to investigate the influence of Sb-modified Mn/PG catalysts.MnSb_(0.156)/PG catalyst showed highest NO conversion at low temperatures in the presence of SO_(2) which reveals that addition of Sb oxides effectively enhances the SCR activity of catalysts.A SO_(2) step-wise study showed that MnSb_(0.156)/PG catalyst displays higher durable resistance to SO_(2) than Mn/PG catalyst,where the sulfating of active phase is greatly inhibited after Sb doping.Scanning electron microscopy and X-ray diffraction results showed that Sb loading enhances the dispersion of Mn oxides on the carrier surface.According to the results of characterization analyses,it is suggested that the main reason for the deactivation of Mn/PG is the formation of manganese sulfates which cause the permanent deactivation of Mn-based catalysts.For Sb-doped Mn/PG catalyst,SO_(x) ad-species formed were mainly combined with SbO_(x) rather than MnO_(x).This preferential interaction between SbO_(x) and SO_(2) effectively shields the MnO_(x) as active species from being sulfated by SO_(2) resulting in the improvement of SO_(2) tolerance on Sb-added catalyst.Multiple information support that,owing to the addition of Sb,original formed MnO_(x) crystallite has been completely transformed into highly dispersed amorphous phase accounting for higher SCR activity.