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Ethanol dehydrogenation is commonly used as a process of production valuable products: acetaldehyde - the starting material for the synthesis of a large number of industrial chemicals such as acetic acid, acetate esters and hydrogen - attractive product for renewable energy. It is important also that alcohols produced from biomass (bio alcohols) can be considered as a renewable raw material. The purpose of this study was to elucidate the effect of composition and synthesis method of Al-Zr-Ce-complex oxides with 5%Cu on its catalytic activity in vapor-phase reactions of ethanol. We investigated the effect of preparation method, phase composition, calcination temperature and Cu-modification of the Zr-Al mixed oxides on their structural features and catalytic performance in bio ethanol conversion. Zirconia-alumina mixed oxides with different atomic ratios were prepared via sol-gel method. Physicochemical properties were determined using XRD, BET and FT-IR-spectroscopy. Catalytic activity and selectivity were investigated for ethanol conversion to acetaldehyde. [ABSTRACT FROM AUTHOR]

In this study, investigation of the composition, structure and catalytic activity of the catalyst support based on Ni-Al mixed oxides was carried out. The possibility of controlling structural and acid-base properties of the layered double hydroxides (LDH) by varying the ratio of M2+/M3+ metal cations determines its use as catalyst support. Besides varying of anions in the interlayer space allows to regulate catalytic system activity in the reaction medium. The Ni-Al LDH support was prepared by coprecipitation method followed by conversion to Ni-Al mixed oxide in the reaction medium. According to the X-ray diffraction analysis, it was shown that the Ni-Al-based mixed oxide obtained with a specific surface area of 158 m2/g contains nickel oxide with a reduced lattice parameter related with the replacement of part of Ni2+ cations with Al3+, phase of mixed oxides of variable composition and amorphous phase. The replacement of Ni2+ by Al3+ in nickel positions is 16%. The crystallite size of the obtained oxide phases is 4 nm. The catalytic activity of Ni-Al mixed oxide was determined in the reactions of the conversion of higher alkanes of the C11-C22 composition, taken in equal proportions, at a temperature of 500°C and a feed to catalyst ratio of 30. According to the chromatographic analysis, alkanes and isoalkanes of composition C7-C14 were formed as catalytic products. Unsaturated compounds in the reaction products were revealed by IR spectroscopy method; the iodine value was 0.172. [ABSTRACT FROM AUTHOR]

During the last decades, problems related to environmental pollution have become even more acute. Therefore there is a need for new sources of a clean energy. Steam reforming of alcohols, which are much morechemically active, proceeds at considerable lower temperatures. It is important also that alcohols produced from biomass (bio alcohols) can be considered as a renewable raw material. The aim of this work were the development of catalysts based on the complex oxides (ZrO2 - Al2O3 - CeO2) support and the study of obtained catalysts behavior in the reaction of ethanol steam reforming in a temperature range 200 - 400°C. We investigated the effect of preparation method, phase composition, calcination temperature and metal modification of the Zr-Al mixed oxides on their structural features and catalytic performance in bio ethanol conversion. Zirconia-alumina mixed oxides with different atomic ratios were prepared via sol-gel method. Physicochemical properties were determined using XRD, BET and FT-IR-spectroscopy. Catalytic activity and selectivity were investigated for ethanol conversion to ethylene, diethyl ether and acetaldehyde. [ABSTRACT FROM AUTHOR]

MgNiAlLa-LDHs (layered double hydroxides) with different La content were synthesized by co-precipitation method and calcined to MgNiAlLa-oxides, and used as heterogeneous base catalysts for transesterification of palm oil with methanol to produce biodiesel, compared to the oxides without Ni (MgAlLaoxide) or La (MgNiAl-oxide). All were characterized by X-ray powder diffraction (XRD) and N2 adsorption-desorption. Metal contents were determined using inductively coupled plasma (ICP) emission spectrometry. Basicity was determined by titration method. Catalytic order of the oxides is: MgNiAlLa (b, high La) > MgAlLa > MgNiAlLa(a, low La) > MgNiAl, related to their basicity. Various parameters influencing the reaction were investigated: methanol/oil molar ratio, temperature and amount of catalyst. The optimum condition for transesterification over the MgNiAlLa(b)-oxide catalyst is: methanol/oil molar ratio of 15, 4 wt% catalyst, 3 h reaction time and at 95 °C yielding 93 %FAME. The catalyst can be reused 4 times and regenerated by washing/calcination to regain its activity. [ABSTRACT FROM AUTHOR]