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Etherification of glycerol with ethanol, both from renewable resources, was studied over heterogeneous catalysts (zeolites of the type BEA, MOR and FAU) and ion-exchange resin Amberlyst 35. The best results were obtained with zeolite H-Beta (CP 814 Q) with the ratio Si/Al = 25. The conversion of glycerol at the temperature of 200 °C was 51,7% at mono-ethyl ethers selectivity of 62% and di- + tri-ethyl ether selectivity of 37,7%. The conversion of glycerol, which was obtained by purification of glycerol phase from MERO production (methyl esters of acids from rape-seed oil), at the same conditions was 50,8%, selectivity to mono-ethers was 71,8% and to di- + tri- ethers 28,1%. Ethers of glycerol have utilization as oxygenate additives to fuels and have positive effect on decreasing particulate matters and carbonyl compounds in exhaust gases.

Palladium-bismuth nanoparticles were supported into strongly basic anion-exchange resin of gel-type and tested as catalysts for the selective oxidation of glycerol with molecular oxygen at atmospheric pressure. Detailed study of the precursors preparation and reduction were undertaken. The catalyst 3%Pd-1%Bi where the bismuth was deposited on the palladium particles (3.4 nm) exhibited at 95% glycerol conversion more than 63% yield toward glyceric acid and tartronic acid after 3 h of reaction. The catalyst maintains practically similar catalytic performance as in fresh state for at least five consecutive catalytic cycles without extra catalyst treatment and reactivation.

Volatile carboxylic acids (mainly acetic acid) can be produced efficiently by simple thermochemical or biological degradation of various biomasses. For the processing of such oxygenates in hydrogen atmosphere, acetic acid (AA) hydroconversion was studied in detail over zeolite-based Ni and bimetallic InNi catalysts in a flow-through reactor at 21 bar total pressure and 240–380 °C. Efficient hydrogenating contacts were already obtained by in situ reduction of Ni-zeolites (A, X, P) and mainly co-reduction of their mixtures with In2O3 in H2 flow at 21 bar and 450 °C. Under these conditions, the bulk of charge-compensating nickel cations remained unreduced and therefore a large portion of the microporous zeolite structure was still preserved. Modification of the formed Ni particles with indium quest metal generated bimetallic NiIn/Ni,H-zeolite catalysts having higher hydroconversion activity with much lowered hydrodecarbonylation and with enhanced ethanol selectivity than the parent partially destructed Ni/Ni,H-zeolite. The activity dependence on the reactant partial pressure denotes rate-controlling surface reaction according to the Langmuir–Hinshelwood mechanism.

Octanoic acid (OA), as model reactant, was hydroconverted in a flow through reactor at 21 bar total pressure and 240–380 °C over various copper catalysts composed with indium or its neighbors in the periodic table (gallium, tin, thallium and cadmium) for comparison. The In-doped sample was proven to be much more advantageous than the other bimetallic analogs tested.

Volatile fatty acids (VFAs) can be produced efficiently by simple thermochemical or biological biomass degradation. For the processing of these organic acids in hydrogen atmosphere, the consecutive reactions of acetic acid (AA) hydroconversion were studied in details looking for conditions of selective ethanol production over a novel and advantageous bimetallic composite applying indium as co-catalyst. The reactions were investigated in vapor phase at 240–380 °C, 7–21 bar hydrogen and 0.5–3.5 bar acetic acid partial pressures in a fixed bed flow-through reactor using supported copper catalysts. In2O3 admission can significantly increase AA hydroconversion activity of copper catalysts supported on various oxides and the yield of the produced ethanol. Efficient hydrogenating catalysts, containing finely dispersed metal particles were obtained by in situ reduction with H2 at 450 °C. In the catalysts modified with In2O3 additive, formation of an intermetallic compound (Cu2In) was strikingly observed resulting in a different, more advantageous catalytic behavior as of pure copper particles supported on different oxide supports. On comparing a commercial, conventionally used catalysts (Adkins: 72 wt% CuCr2O4 + 28 wt% CuO) with the bimetallic alumina supported composite (Cu2In/Al2O3) the new catalyst proved to be much more active and selective for producing ethanol. A schematic representation of reactions involved in the hydroconversion of acetic acid was explored and verified. The activity dependence on the reactant partial pressures denotes rate-controlling surface reaction according to Langmuir–Hinshelwood mechanism.

Octanoic acid (OA) was hydrotreated in a flow-through reactor at 21 bar total pressure and 240–340 °C over supported metal catalysts prepared from Ni-zeolites (A, X, P) by indium modification. The Ni-zeolites were activated first in H2 flow at 21 bar and 450 °C. While a fraction of the nickel got fully reduced, the zeolite structure became partially destructed. However, some nickel cations remained unreduced, therefore a large fraction of the crystalline zeolite structure was retained. The indium modification of the reduced Ni-zeolites generated bimetallic NiIn/Ni,H-zeolite catalysts having higher stability, hydroconversion activity, octanol selectivity, and lower hydrodecarbonylation activity than the parent partially destructed Ni-zeolite and the Adkins-type catalysts, commercially applied for the conversion of fatty acids to alcohols.

Octanoic acid (OA) was used as reactant with medium chain length to model the aliphatic carboxylic acids which can be produced by catalytic, thermochemical or biological degradation of biomass. A flow through reactor was applied at 21 bar total pressure (in general at 20 bar hydrogen and 1 bar octanoic acid partial pressures) and 330–380 °C. Cu A-, X- and Y-zeolite based catalysts were pretreated in hydrogen flow at 450 °C. During reduction/dehydration A- and X-zeolite structures collapsed and aluminosilicate supported copper catalysts were formed, which contain copper nanoparticles in high dispersion. The catalyst samples were modified by In2O3 co-catalyst. Fatty acid conversion activity of amorphized zeolite supported Cu catalysts and the yield of selectively produced alcohol can be increased drastically by In2O3 addition. Appearance of metallic indium can effectively rein in the step by step catalytic reduction at alkanol formation previous to dehydration of alcohols to alkenes and ethers.

There are intensive efforts for reforming triglycerides to fuels. A non-pyrophoric Raney nickel type catalyst was investigated in the hydroconversion of sunflower oil. The catalyst was also tested in the transformation of octanoic acid as a model compound at 21 bar in temperature range of 280–340 °C. It was found that alumina supported Ni catalysts (one of them is non-pyrophoric Raney type Ni) selectively catalyze the hydrodecarbonylation and decarboxylation of fatty acids being corrosive intermediates of trigliceride deoxygenation process. Beside the main hydrodecarbonylation reaction Ni-containing catalysts are active in disadvantageous side reactions such as CO methanization and hydrogenolysis of paraffins producing methane byproduct in high concentration with extensive hydrogen consumption. Non-pyrophoric Raney nickel catalyst is more active than Ni/Al 2 O 3 samples especially in the side reactions. To eliminate the active sites responsible for the side reactions the catalyst was modified with tin and lead. It turned out that poisoning either with Sn or Pb did not improve selectivity. Finally addition of In 2 O 3 proved to be effective by directing the transformation to a different deoxygenating reaction pathway resulting in high alcohol yields.

This work relates to the consecutive reduction of short chain carboxylic acids (volatile fatty acids, VFAs) to alcohols as main products. Acetic acid (AA) was used as a reactant to model the VFAs that can be produced by either thermochemical or biological biomass degradation. The amorphised zeolite supported copper catalysts (Cu/SiAl), especially the In-modified CuIn/SiAl catalysts, showed high hydroconversion activity and selectivity for alcohol, ester and aldehyde. Catalysts containing dispersed copper particles in amorphous aluminosilicate were obtained by dehydrating and H2-reducing Cu-forms of low-silica synthetic zeolites (A, X, P). The activity of the highly destructed Cu-aluminosilicates was found to depend on the structure of the zeolite precursor. The formation of ethyl acetate could be suppressed by adding water to the AA feed and by modifying the catalyst, e.g. by In2O3 additive. In the catalysts modified by In2O3 additive formation of copper-indium alloy phase (Cu2In intermetallic compound) was detected resulting in a different selectivity than the one recorded for the Cu/SiAl.

Consecutive reduction of acetic acid (AA) to ethanol was studied looking for an advantageous catalyst for the processing of VFAs (volatile fatty acids) that can be produced by thermochemical or biological biomass degradation. A fixed bed flow-through reactor was applied with hydrogen stream at 21 bar total pressure in the temperature range of 220–380 °C. AA hydroconversion activity of the parent alumina supported Ni catalyst and the yield of selectively produced alcohol can be increased drastically by In2O3 addition. Efficient catalysts, containing finely dispersed metal particles were obtained by reduction with H2 at 450 °C. In the catalysts modified with In2O3 additive formation of indium metal and/or an intermetallic compound (InNi2) was observed resulting in a different catalytic behavior as for pure nickel particles supported on alumina. Appearance of metallic indium can direct the step by step catalytic reduction to ethanol formation inhibiting decarbonylation, decarboxylation, and additional dehydration. On comparing the commercial, conventionally used catalysts with the bimetallic alumina supported composite (InNi/Al2O3) the novel catalyst proved to be much more active and selective for producing ethanol.

The catalytic hydrodeoxygenation (HDO) of octanoic acid (C7COOH) to octene and octane was found to proceed in consecutive reaction through octyl aldehyde and octyl alcohol intermediates. Aluminosilicate and γ-alumina supported Cu and Cu,In catalysts were applied in a fixed bed flow-through reactor at 21 bar total pressure in the temperature range of 330–380 °C. The feed was 7.1% C7COOH/84.3% H2/He. The WHSV of the acid was 1.82 h−1. The results suggested that at lower temperatures the rate of acid hydrogenation/dehydration determined the rate of the consecutive hydroconversion process and alcohol selectivity. The reduction of aldehyde was facile, thus, the aldehyde selectivity was low under most conditions. At lower temperatures and conversions the acid coverage was high hindering the catalytic dehydration of the product alcohol. At higher temperatures and acid conversions the alcohol dehydration activity of the catalyst determined the alcohol selectivity. The indium additive was found to increase the HDO activity and the alcohol selectivity of the copper catalysts significantly. The favorable effects of indium were attributed to the formation of new catalytically active Cu2In alloy phase.

Octanoic acid (OA) as model reactant of medium chain length, and its reduced products, octanal and octanol were hydroconverted over different components of a CuIn/Al2O3 composite catalyst. A fixed‐bed flow through reactor was used at 21 bar total pressure in the temperature range of 240–360 °C. Fatty acid hydroconversion activity of alumina supported Cu catalyst and mainly the yield of selectively produced octanol can be greatly increased by In2O3 doping, suppressing the dehydration side reactions. Appearance of metallic indium on alumina supported reduced copper catalyst can arrest the consecutive catalytic reaction at the alcohol formation step prior to further dehydration to ether or alkenes. An industrial, conventionally used Adkins catalyst (72 wt.% CuCr2O4 and 28 wt.% CuO) and the novel bimetallic composite (CuIn/Al2O3) were compared: both produce octanol with high selectivity, but the new chromium‐free fatty acid hydrogenation catalyst is more active, nearly as active as earlier investigated NiIn/Al2O3.

Octanoic acid (OA) was used as reactant with medium chain length to model the aliphatic carboxylic acids which can be produced by catalytic, thermochemical or biological degradation of biomass. A flow through reactor was applied at 21 bar total pressure (in general 20 bar hydrogen and 1 bar octanoic acid partial pressures) and 240–360 °C. Fatty acid conversion activity of alumina supported Ni catalysts and the yield of selectively produced alcohol can be increased drastically by In 2 O 3 doping. Appearance of metallic indium can effectively direct the step by step catalytic reduction to alcohol formation over partly reduced Ni catalysts instead of chain shortening hydrodecarbonylation. On comparing a commercial, conventionally used Adkins catalyst (consisting of 72 wt.% CuCr 2 O 4 and 28 wt.% CuO) and novel bimetallic alumina supported composite (InNi/Al 2 O 3 ) producing alcohol with high selectivity, the chromium-free, environmental benign hydrogenation catalyst seems to be much more active.

Hydroconversion of caprylic acid as model compound was studied in a flow-through fixed-bed reactor at 21 bar total pressure and 240-360 °C reaction temperature over various hydrogenating active phases: pure metal (Cu, Ni) and intermetallic compound (Cu(2)In, Ni(2)In) nanoparticles. Different silicas produced by dissimilar methods and a commercial gama-alumina were compared as appropriate supports. Catalyst precursors were activated in reducing H(2) flow at 21 bar and 450 °C as routine pretreatment. Catalysts of high activity and selectivity for alcohol production can be obtained by varying the supports, the main metals and their indium modified bimetallic forms. Diversity of catalytic behavior reflects the complexity of the surface reactions. Caprylic alcohol formation was substantiated to proceed through caprylic aldehyde intermediates, however it can be also dehydrated to dicaprylic ether or octenes over alumina support. Silica supports, especially a less compact variant seem to be more inert for side reactions than alumina. Different morphology of studied silicas can highly influence the catalytic performances taking place over different metal particles.

Consecutive hydroconversion of acetic acid (AA) to ethanol was compared over monometallic and novel bimetallic (containing In as guest metal) catalysts on alumina and silica supports (inter alia highly ordered SBA-15) of different porosity and pore structure. The transformation was studied in a fixed bed, flow-through reactor in the temperature range of 220–380°C using hydrogen flow at 21 bar total pressure. AA hydroconversion activity of Cu and Pt catalysts and the yield of selectively produced alcohol were increased drastically by applying SBA-15 as highly ordered, mesoporous silica support instead of alumina. The most active nickel catalysts do not allow the selective addition of hydrogen to carbon-oxygen bonds independently of supports producing mainly CH4; however, indium doping can completely eliminate the hydrodecarbonylation activity as found in earlier studies. The textural properties of studied silica supports of various textures such as SBA-15, CAB-O-SIL, and Grace Sylobead have a profound impact on the catalytic performance of Ni and Ni2In particles.