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The aldol condensation of furfural and acetone is considered a promising method for the production of liquid fuel intermediates. 4-(2-furyl)-3-buten-2-one (FAc) and 1,5-di-2-furanyl-1,4-pentadien-3-one (F2Ac) are the main products of the reaction, which can go through the hydrodeoxygenation process to convert to diesel and jet fuel range fuels. Considering the present situation at the fuel-market related to crude oil shortage, the above-mentioned process seems to be a convenient path to obtain fuels in the diesel and kerosene range. This research focuses on the effect of water on the furfural conversion and product distribution during the aldol condensation. The catalyst chosen for this research was MgAl mixed oxide in molar ratio 3:1. The reaction was performed at 40 °C and 1 MPa in a continuous-flow reactor with and without water in the feedstock. The physicochemical properties of the catalyst were evaluated using different techniques. The catalyst lifetime decreased and the catalyst deactivation started faster by the addition of 5 wt.% water to the feedstock with the furfural to acetone ratio (F:Ac) of 1:2.5. Selectivity to FAc increased by 10% in the presence of water. The catalyst lifetime enhanced by increasing the F:Ac ratio from 1:2.5 to 1:5, in the presence of 5 wt.% water. The furfural conversion was 100% after 28 h of reaction, and then decreased gradually to 40% after 94 h of reaction. At higher F:Ac ratio, the selectivity to FAc was 10% higher, while the F2Ac was about 8% lower. [ABSTRACT FROM AUTHOR]

Transition metal nitrides, carbides and phosphides have the potential to replace the expensive and hazardous catalysts typically used for the conversion of fatty acids. However, there has been little research on the influence of treatment conditions and precursor nature on the properties of such catalytic systems. To better understand these dependencies, we synthesized a number of Mo catalysts by temperature‐programmed reduction (700‐900 °C; CH4/N2, N2/H2) using ammonium heptamolybdate, diammonium phosphate and hexamethylenetetramine (HMT) as Mo, C, N and P sources. The presence of HMT in the precursor mixtures ensured the synthesis of pure phase Mo2C, Mo2N and MoP. Catalytic activity in the (hydro)deoxygenation of stearic acid (240 min; 360 °C; 50 bar of H2) decreased in the following order: Mo2C>Mo2N>MoP. However, all of the studied Mo‐based catalysts showed good deoxygenation efficiency and, thus, represent excellent alternatives to traditional noble and sulfur‐containing catalysts. [ABSTRACT FROM AUTHOR]

A process of transforming hydrotalcite, containing Cu-Zn-Al (2:1:1) to a catalysts for selective hydrogenolysis of glycerol to 1,2-propanediol has been studied. A two steps process, consisted of the calcination at increased temperature and subsequent reduction with hydrogen, as well as a one step process, in which the hydrotalcite was heated at hydrogen atmosphere so the calcination and reduction were joined to one operation, were verified experimentally. The influence of the temperature in the calcination step in the two steps process on composition, texture and catalytic properties of the active form of catalyst has been studied in detail. X Ray diffraction, thermogravimetric analyses, nitrogen physisorption, mercury porosimetry, temperature-programmed reduction and high-resolution transmission electron microscopy were used for the catalysts characterization. A study of calcination of a Cu-Zn-Al containing hydrotalcite at different temperatures showed, that at temperature ending with 350 °C, predominantly amorphous, mixed oxides containing phase was formed. The most active and most selective catalyst was obtained by the reduction of this amorphous oxide phase. In contrary, highly crystalline material was obtained at higher calcination temperatures, i.e at 450 or 700 °C respectively, but the activity of the reduced form of these crystalline oxides was lower. It was also proven, that by simultaneous calcination and reduction, a catalyst of the same activity and even better selectivity towards 1,2-propanediol could be prepared, comparing with the catalyst prepared by the two steps method. [ABSTRACT FROM AUTHOR]

In this work, we studied the effect of molybdenum precursors and the synthesis conditions on the final phase composition of bulk and supported molybdenum carbides and nitrides. Ammonium heptamolybdate, its mixture with hexamethylenetetramine, and their complex were used as the precursors at different temperatures. It was investigated that the synthesis of the target molybdenum nitrides strongly depended on the structure of the precursor and temperature conditions, while the synthesis of carbide samples always led to the target phase composition. Unlike the carbide samples, where the α-Mo2C phase was predominant, the mixture of β-Mo2N, MoO2 with a small amount of metal molybdenum was generally formed during the nitridation. All supported samples showed a very good dispersion of the carbide or nitride phases. [ABSTRACT FROM AUTHOR]