A series of monometallic platinum and bimetallic platinum−rhenium catalysts supported on mesoporous carbon Sibunit, which is a type of mesoporous, microcrystalline carbon, were investigated for hydrodeoxygenation (HDO) of isoeugenol (IE) at 200−300 °C and 30 bar of H 2 , using dodecane as a solvent. Catalytic activity was tested in a batch reactor to screen the catalysts and, for comparison, also in the continuous mode. For batch experiments, complete conversion, and a high yield of the desired product, propylcyclohexane (PCH), were obtained for all bimetallic PtRe/Sibunit in 240 min, with the highest yield of PCH when Pt:Re ratio was 1:1 or 1:3. The results for Pt−Re (1:1) were reproducible, in terms of catalytic activity and reusability of catalysts, which showed no deactivation. Monometallic Pt catalysts displayed low activity. Continuous experiments were performed with PtRe(1:1)/Sibunit at 30 bar H 2 , 0.5 mL/min of the liquid flow, and temperatures between 75 °C and 200 °C. The distribution of products showed deoxygenation at higher temperatures, while at lower temperatures, mainly oxygenated products were formed. XPS results confirmed the presence of ReOx species, where an increase in the platinum loading resulted in a decrease in the fraction of ReOx species and subsequently lower PCH yield.
The one-pot synthesis of menthol from citral in a continuous mode was investigated over three different types of extrudates, namely Ni supported on H-Beta-38 and extruded with attapulgite, Ni supported on attapulgite and extruded with H-Beta-38, and the extrudates, which were shaped after deposition of Ni on both H-Beta-38 and attapulgite in the powder form. These composite catalysts were characterized by X-ray diffraction, transmission and scanning electron microscopy, temperature-programmed reduction of H 2 , mechanical strength, and pyridine adsorption desorption. These three types of extrudates exhibited different metal particle sizes and acidity. The most promising catalyst in the one-pot menthol synthesis was Ni supported first on H-Beta-38 and then extruded with attapulgite giving a 45% yield of menthols in a trickle bed reactor. This catalyst exhibited 10 nm nickel particles and a rather high amount of strong Brønsted acid sites.
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