Search

Your search keyword '"Szabolcs Harnos"' showing total 3 results
Start Over Author "Szabolcs Harnos" Language english
3 results on '"Szabolcs Harnos"'

1. Bioacid Hydroconversion over Co, Ni, Cu Mono- and Indium-doped Bimetallic Catalysts

Author

György Onyestyák, Szabolcs Harnos, and Dénes Kalló

Subjects
Carboxylic acids, hydroconversion, alcohols, indium doping, Chemistry, QD1-999
Abstract

Caprylic acid (CA) as model reactant was selectively reduced in a flow-through reactor in hydrogen stream at 21 bar total pressure and 240-360 °C over alumina loaded with the adjacent Co, Ni, Cu host and In guest metals. The main target of this research is the recognition of efficient cobalt catalysts for carboxylic group hydroconversion compared to more familiar nickel and copper composites. The catalysts were activated in H2 flow at 21 bar and 450 °C. By variation of main metal or modification with indium, mono- or bimetallic catalysts can be obtained with low hydrodecarbonylation activity and high alcohol selectivity. These composites have higher hydrodeoxygenation (HDO) activity and alcohol selectivity than the conventional commercial catalysts applied for fatty alcohol production. Great variety of catalytic behavior indicates complexity of the surface reactions determined by several interacting factors.

Published
2015
Full Text
View/download PDF

2. Novel Cu and Cu2In/aluminosilicate type catalysts for the reduction of biomass-derived volatile fatty acids to alcohols

Author

Szabolcs Harnos, Magdaléna Štolcová, György Onyestyák, Alexander Kaszonyi, József Valyon, and Róbert Barthos

Subjects
chemistry.chemical_classification, ethyl acetate, cu-zeolites, Chemistry, in2o3 doping, Ethyl acetate, Alcohol, General Chemistry, Aldehyde, Catalysis, Acetic acid, chemistry.chemical_compound, Aluminosilicate, Materials Chemistry, acetic acid reduction, Organic chemistry, ethanol, Selectivity, Zeolite, QD1-999
Abstract

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.

Published
2012

3. Acetic acid hydroconversion over mono- and bimetallic indium doped catalysts supported on alumina and silicas of various textures

Author

Szilvia Klébert, György Onyestyák, Eszter Drotár, Dénes Kalló, Szabolcs Harnos, and Cecília A. Badari

Subjects
bimetallic catalyst, Ethanol, Chemistry, acetic acid hydroconversion, indium co-catalyst, Inorganic chemistry, Doping, chemistry.chemical_element, General Chemistry, sba-15, Catalysis, chemistry.chemical_compound, Acetic acid, Materials Chemistry, ethanol, Bimetallic strip, QD1-999, Indium
Abstract

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.

Published
2014

Catalog

Books, media, physical & digital resources
See catalog results