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The alkylation of benzene with propane to yield isopropylbenzene proceeds with high selectivity over bifunctional metal-acid catalysts comprising Pt and Keggin heteropoly acid in a fixed-bed reactor at 250-350 o C and 1 bar pressure. Most efficiently the reaction occurs over Pt/H 4 SiW 12 O 40 /SiO 2 catalyst at 300 o C, giving isopropylbenzene with 90-93% selectivity at 6-8% benzene conversion, significantly exceeding the efficiency of previously reported Pt/HZSM-5 catalyst. The alkylation proceeds through bifunctional reaction pathway including dehydrogenation of propane to propene (1) on Pt sites followed by benzene alkylation with propene (2) on acid sites. At Pt loadings above 0.5%, step (1) is at fast quasi-equilibrium, and step (2) is the rate-limiting one.

Amorphous silica and crystalline silicalite (MFI structure) are demonstrated to be active and environmentally benign catalysts for propionic acid ketonisation at 450-500 °C to form 3-pentanone. The silicalite is particularly efficient, and its ketonisation selectivity is increased by base modification probably through generation of silanol nests.

Ketonization of acetic acid was carried out in the gas phase over bulk and supported cobalt-molybdenum catalysts using a fixed-bed reactor. The conditions of the reaction were: 0.2 g of catalyst, 200-400°C, 1 bar pressure, 2 vol% of acetic acid and 20 mL min −1 of nitrogen flow. Bulk and supported catalysts were prepared and calcined at 400°C in N 2 flow for 3 h to obtain metal oxides. Both bulk and supported catalysts were tested in the ketonization reaction of acetic acid to form acetone. They have been found active catalysts in this reaction. The catalytic activity was enhanced further by supported catalysts. 20% Co-Mo/Al 2 O 3 catalyst showed superior catalytic performance in the ketonization of acetic acid, with 95% of acetone selectivity at 96% of acetic acid conversion at 380°C, 1 bar and 20 mL min −1 of N 2 flow. These materials were characterized by thermogravimetric analysis, nitrogen sorption and FTIR using pyridine adsorption.

It was demonstrated that iron molybdate catalysts for methanol oxidation can be prepared using Fe(II) as a precursor instead of Fe(III). This would allow for reduction of acidity of preparation solutions as well as elimination of Fe(III) oxide impurities which are detrimental for the process selectivity. The system containing Fe(II) and Mo(VI) species in aqueous solution was investigated using UV-Vis spectroscopy. It was demonstrated that three types of chemical reactions occur in the Fe(II)-Mo(VI) system: (i) formation of complexes between Fe(II) and molybdate(VI) ions, (ii) inner sphere oxidation of coordinated Fe(II) by Mo(VI) and (iii) decomposition of the Fe-Mo complexes to form scarcely soluble Fe(III) molybdate, Mo(VI) hydrous trioxide and molybdenum blue. Solid molybdoferrate(II) prepared by interaction of Fe(II) and Mo(VI) in solution was characterized by EDXA, TGA, DTA and XRD and a scheme of its thermal evolution proposed. The iron molybdate catalyst prepared from Fe(II) precursor was tested in methanol-toformaldehyde oxidation in a continuous flow fixed-bed reactor to show similar activity and selectivity to the conventional catalyst prepared with the use of Fe(III).

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Metal oxides such as Nb2O5, Cr2O3, and especially a ZnIICrIII mixed oxide are demonstrated to be highly active and recyclable heterogeneous catalysts for Prins condensation, which provides a clean, high‐yielding route for the synthesis of nopol through the condensation of biorenewable β‐pinene with paraformaldehyde. ZnCr mixed oxide with an optimum Zn/Cr atomic ratio of 1:6 gave 100 % nopol selectivity at 97 % β‐pinene conversion, with the catalyst easily recovered and recycled. The acid properties of Nb2O5 and ZnCr mixed oxide were characterized by the diffuse reflectance IR Fourier transform spectroscopy of adsorbed pyridine and ammonia adsorption microcalorimetry. An appropriate combination of acid–base properties of ZnCr mixed oxide is believed to be responsible for its efficiency.

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