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The microwave-assisted conversion of levulinic acid (LA) has been studied using low-loaded supported Fe-based catalysts on porous silicates. A very simple, productive, and highly reproducible continuous flow method has been used for the homogeneous deposition of metal oxide nanoparticles on the silicate supports. Formic acid was used as a hydrogen donating agent for the hydrogenation of LA to effectively replace high pressure H2 mostly reported for LA conversion. Moderate LA conversion was achieved in the case of non-noble metal-based iron oxide catalysts, with a significant potential for further improvements to compete with noble metal-based catalysts

SBA-15 materials exhibit important properties including large surface area, highly ordered mesopores, and high stability in a variety of catalytic reactions. In this study, Al and Zr-loaded SBA-15 materials (Si/Zr = 30, Si/Al = 30), 50 molar ratio with Pd (1, 2, and 4% (w/w)) and Pt (0.5 and 1% (w/w)) were tested in the isomerization of C5-C7 linear alkanes. These solids were characterized using thermal gravimetric analysis-differential thermal analysis (TGA-DTA), nitrogen physisorption, and energy dispersive X-ray (EDX). Interestingly, the low porosity SBA-15 materials loaded with 2% (w/w) Pd were most active catalysts for n-heptane isomerization. The mechanochemical addition of tungsten also resulted in the increase of catalytic activity for the reaction. The results herein demonstrate the possibilities of SBA-15 catalysts as a commercial catalyst alternative in the catalytic isomerization of hydrocarbons.

Catalytically active supported metal nanoparticles on aluminosilicates including Cu and Pd-based systems were investigated in the microwave-assisted conversion to a range of valuable furanic compounds via tandem formic acid-promoted dehydration and subsequent selective hydrogenation processes. Results show that interesting selectivities to reduced products including 5-methylfurfural and 5-methylfurfuryl alcohol as well as hydroxymethylfurfural and furfural could be obtained in various proportions depending on the type of catalyst and the investigated reaction conditions. The investigation of reaction parameters including time of reaction, type of catalyst, quantity of catalyst and formic acid content indicated that reaction conditions can in principle be fine-tuned to maximise selectivity towards individual products.

Iron-modified AlPO4 catalysts (0.5–5 wt.% Fe2O3) have been prepared by impregnation until incipient wetness with different iron(III) salts. The resulting solids, after characterization by surface area, XRD and DRIFT measurements, were checked for their surface acidity through their catalytic activity towards cyclohexene skeletal isomerization test reaction. It was found that iron(III) increases the catalytic performance of AlPO4 and besides, the iron(III) salt used strongly influences the activity. Thus, the catalysts prepared using complexed iron(III) salts as starting materials presented higher specific activity (and hence, acidity) than those prepared using iron(III) nitrate. Moreover, a maximum in activity was found for 2 wt.% Fe2O3.

The Michael addition of nitromethane to 3-buten-2-one has been carried out in the absence of solvent, using potassium fluoride supported on Al2O3, ZnO, SnO2, sepiolite, AlPO4, AlPO4−Al2O3 and AlPO4−ZnO catalysts. We found that KF/ZnO easily performed the Michael addition and thus, ZnO is a better support for the basic reagent than Al2O3. Besides, the Michael addition was not successful with AlPO4 or AlPO4-metal oxide acidic supports.

A series of FePO4(Fe/P = 1) catalysts have been prepared by precipitation of the corresponding chloride or nitrate iron(III) salt and orthophosphoric acid with aqueous ammonia or propylene oxide at pH 7.0. The resulting solids, after calcination at temperatures in the range 673–1273 K for 3 h, were characterized by surface area, X-ray diffraction (XRD) and diffuse reflectance IR (DRIFT) measurements.All catalysts were amorphous for calcination temperatures below 923 K. Calcination at 923–1273 K develops FePO4 with a quartz-like phase structure (ASTM 29–715). Amorphous samples exhibited relatively high surface areas which fell sharply as crystallization of FePO4 occurred. Moreover, the surface acidity (Bronsted and Lewis), characterized by adsorption of pyridine using a pulse method and DRIFT measurements, strongly depended on the preparation method causing the amorphous FePO4 catalysts, obtained from iron(III) chloride and aqueous ammonia, to be more acidic. This increased surface Bronsted acidity was responsible for their improved performance in cyclohexene skeletal isomerization (CSI). FePO4 catalysts also showed catalytic activity for cyclohexene dehydrogenation to benzene.

The nature of supported KMnO4 reagents on several solids (SiO2 AlPO4, BPO4 and sepiolite) is discussed. The oxidation of PhCHO to PhCO2H was the test reaction. The KMnO4 supported reagent is shown to be a mixture of physisorbed KMnO4 and Mn(IV). The influence of the nature of the solvent is discussed.

We have analyzed the influence of the chemical and textural properties of the solid supports as well as the oxidising K2Cr2O7 supported reagent on the oxidation of menthol to menthone—as a reaction test—. The most active K2Cr2O7 supported reagents are obtained with amorphous solid supports with large surface areas or with microcrystalline solids, with great amounts of oxidising sites titrated by phenothiazine.

The liquid phase reduction of different substituted nitrobenzene derivatives with the formic acid-triethylamine system has been carried out by the use of a supported palladium (0,6%) on AlPO4/SIO2 (20:80 weigth) catalyst. The reduction rate of nitrocompounds containing electron-acceptor substituents is much higher than that of electron donor-containing substrates.

The oxidation of benzyl halides by DMSO in presence of barium hydroxide as catalyst in the heterogeneous phase is described. The reaction is optimized. The influence of halide and benzyl halide ring substituent on the yield is discussed. The mechanism for the heterogeneous process is discussed.

Several K 2 Cr 2 O 7 supported reagents on inert solids have been obtained by deposition of K 2 Cr 2 O 7 on different solids.A1PO ,BPO and solid mixtures BPO -A1PO are used as supports. The K 2 Cr 2 O 7 is deposited on solid as large crystals detected by an X-ray diagram in the Cr50 and Cr25 series giving solids with very low surface areas.The number of acid and oxidizing sites is dtermined.Solids supports with small surface areas and large pore diameter give K 2 Cr 2 O 7 supported reagents with higher activity than those obtained from solids with high surface areas and large pores.

Preparation d'(alcene-1'yl-2) furannes a partir du furfural et d'(alkyl trimethyl) phosphoniums

Several new supported K2Cr2O7 reagents are used in the oxidation of secondary alcohols. The influence of the number of active sites and the nature of solid support on the yield is discussed. The influence of the structure of alcohol on the yield of ketone is analyzed.

Using an interactive software program, Virtual Chemistry Laboratory (VCL), we conducted an educational experiment to assess the software's influence on student understanding of some basic organic chemistry laboratory techniques. First-year engineering students at the Superior Polytechnic School of Cordoba were evaluated: more favorable results were obtained from students who had worked with the VCL when compared to results of students who had not worked with the VCL. We conclude that the use of VCL helps students gain a better understanding of the techniques and basic concepts used in the laboratory work. Use of the program particularly contributes towards improving the progress of those students with the greatest learning difficulties.