Jerzy Haber Institute of Catalysis and Surface Chemistry

Kraków, Poland

Jerzy Haber Institute of Catalysis and Surface Chemistry

Kraków, Poland

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Guesmi H.,National Graduate School of Chemistry, Montpellier | Grybos R.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Handzlik J.,Cracow University of Technology | Tielens F.,CNRS Laboratory of Condensed Matter Chemistry, Paris
RSC Advances | Year: 2016

A DFT based characterization of tungsten oxide supported on amorphous hydroxylated silica is presented. The different molecular organizations are investigated on the surface topology and tungsten oxygen coordination. The presence of mono- and di-grafted species is discussed and rationalized, using an atomistic thermodynamic approach. The presence of W O groups are preferred over W-OH groups and the grafting coordination is dominated by the degree of hydration of the silica surface. At room temperature di-oxo digrafted and mono-oxo-tetragrafted species are in competition regulated by the ambient degree of hydration which also affects the silanol density of the silica support. A comparison between tungsten and the other group VI elements confirms a greater chemical difference with Cr than with Mo. © The Royal Society of Chemistry 2016.


Patent
Ibm, Conpart AS, Intrinsiq Materials and Jerzy Haber Institute Of Catalysis And Surface Chemistry | Date: 2015-10-12

A bridging arrangement includes a first and a second surface defining a gap therebetween. At least one surface of the first and second surface has an anisotropic energy landscape. A plurality of particles defines a path between the first and second surface bridging the gap.


Tokarz-Sobieraj R.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Grybos R.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Filek U.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Micek-Ilnicka A.,Jerzy Haber Institute of Catalysis and Surface Chemistry | And 3 more authors.
Catalysis Today | Year: 2015

The catalytic properties, both redox and acidic, of 12-tungsto- and 12-molybdo-phosphoric Al3+, Ga3+, In3+ salts were studied. As a model reaction the gas phase ethanol conversion was used. On different sites (redox and acidic) various products are obtained (acetaldehyde and diethyl ether/ethylene respectively). Catalytic activity of MePW and MePMo salts was theoretically predicted, using both periodic and cluster models. Performed experiments confirm the theoretical prediction concerning the influence of addenda atoms (W and Mo) and various counter-cations (Al3+, Ga3+, In3+) on the catalytic properties of studied systems. © 2015 Elsevier B.V. All rights reserved.


Lalik E.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Kosydar R.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Tokarz-Sobieraj R.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Witko M.,Jerzy Haber Institute of Catalysis and Surface Chemistry | And 6 more authors.
Applied Catalysis A: General | Year: 2015

The thermal effects and activity of silica and alumina supported monometallic Pd, Pt and bimetallic Pd-Pt catalysts (of various Pd/Pt ratio) in the exothermic H2 and O2 recombination reaction have been investigated in view of their potential use in the industrial passive autocatalytic recombiners (PAR). The pattern of changes in both the heat evolution and the conversion of hydrogen observed in the H2/O2 reaction seem to reflect the effect of water formation on the activity/deactivation of the studied catalysts. The catalysts have been prepared using the colloid-based reverse "water-in-oil" microemulsion method and characterized by XRD, XPS, SEM, EDS techniques. The recombination reaction of hydrogen and oxygen has been monitored using Microscal gas-flow through microcalorimeter as well as a laboratory flow microreactor. The humidity present in the reaction mixture and the water molecules formed in the recombination reaction both inhibited the activity of the tested catalysts. The nature of support and the type of metal played a role in such water-poisoning effect. Deactivation of alumina supported catalysts was stronger than silica supported counterparts and Pt was more prone to the water inhibition compared to Pd. The most promising catalysts exhibiting the lowest amount of evolved heat accompanied by high and stable activity are silica supported Pd-rich bimetallic Pd-Pt particles whereas alumina wash-coat-Pt is the catalyst of chose in the PAR reactors. The observed activity/water-poisoning relations found confirmation in the DFT calculations concerning the interactions between water molecules and mono-(Pd, Pt) as well as bi (Pd-Pt) metallic clusters as a function of cluster size and Pd/Pt compositions. © 2015.


Lalik E.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Drelinkiewicz A.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Kosydar R.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Rojek W.,Jerzy Haber Institute of Catalysis and Surface Chemistry | And 5 more authors.
International Journal of Hydrogen Energy | Year: 2015

Activity and deactivation of alkali (Li, Cs) doped 2%Pd/Al2O3 catalyst in the exothermic H2 and O2 reaction have been studied in view of potential application in the passive autocatalytic recombiners (PAR), the safety devices applied in the nuclear plant containments to lower the explosion risk associated with hydrogen release. The catalysts have been prepared with impregnation method and characterized by BET, XPS, TEM and STEM techniques. The role of humidity in the H2/O2 recombination reaction has been studied in a flow laboratory reactor using water saturated reaction mixture (0.5 vol% H2). The time-on-stream behavior of catalyst in contact with reaction mixture of high H2 concentration (7.2 vol%) has been studied using Microscal gas-flow through microcalorimeter. The thermal effects accompanying the H2 conversion during slow deactivation of catalysts have been monitored. The pattern of changes in both the heat evolution and the H2 conversion in the Pd-catalyzed H2/O2 recombination reaction seem to reflect the inhibiting effect of humidity present in the reaction mixture and water molecules formed in the reaction. The presence of both Li and Cs enhanced deactivation of Pd/Al2O3 catalyst and Cs-dopant displayed more pronounced effect. On the other hand, the alkali dopants do not essentially affect the amount of heat evolved during the recombination process ranging from 187 to 220 kJ/mol H2, e.g. being lower than the heat of water formation (246 kJ/mol). The detrimental effect of Li,Cs dopant has been attributed to higher affinity to water, promoting retention of water molecules/films on the catalyst surface and blockage of active sites due to enhanced adsorption of surface species, like H2O/OH. © 2015 Hydrogen Energy Publications, LLC.


Lalik E.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Drelinkiewicz A.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Kosydar R.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Tokarz-Sobieraj R.,Jerzy Haber Institute of Catalysis and Surface Chemistry | And 4 more authors.
Applied Catalysis A: General | Year: 2016

The thermal effects and activity of silica and alumina supported bimetallic Pd-Au catalysts (of various Pd/Au ratio) in the exothermic H2 and O2 recombination reaction have been investigated in view of their potential use in the industrial passive autocatalytic recombiners (PAR). The catalysts were prepared by the colloid-based reverse “water-in-oil” microemulsion method which provided metal particles of size in a very narrow range (4–7 nm). In both SiO2 and Al2O3 − series catalysts the Pd-Au particles aggregated to some extent, especially strongly in alumina-series samples. The H2 + O2 reaction has been monitored using Microscal gas-flow through microcalorimeter at temperature of 22 °C and atmospheric pressure. The observed pattern of changes in both the heat evolution and the conversion of hydrogen seem to reflect the effect of water and/or other oxygen-containing surface species (like OH) on the activity/deactivation of catalysts. The nature of support and the composition of metal particles (Pd/Au ratio) played a role. Deactivation of alumina supported catalysts was stronger than silica supported counterparts. Among all studied catalysts, the best behavior was offered by low Au content-containing Pd-Au-0.1/SiO2 (Pd90Au10) catalyst. Its almost stable activity during the catalytic run may be attributed to relatively weak interactions with water molecules and/or other oxygen-containing species (like OH), intermediates formed in the hydrogen oxidation. It may be supposed that electronic modification of palladium sites by gold assisted by the surface composition of Pd-Au particles reflecting in “surface arrangement of Pd and Au-atoms” are decisive. This experimental observation seems to correlated with the DFT calculation indicating that besides the number of Au atoms, their location with respect to the Pd, e.g “surface arrangement of Au” is more important for the energy/strength of interaction with water molecules. © 2016 Elsevier B.V.


Kolodziej M.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Drelinkiewicz A.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Lalik E.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Gurgul J.,Jerzy Haber Institute of Catalysis and Surface Chemistry | And 2 more authors.
Applied Catalysis A: General | Year: 2016

Liquid phase hydrogenation of cinnamaldehyde (CAL) is studied at mild conditions (50 °C, atmospheric pressure) on molybdena-supported Pd catalysts (0.5-4 wt% Pd) to elucidate an effect of hydrogen bronzes in controlling the selectivity to C=C/C=O hydrogenation. The Pd/SiO2 catalyst is used as a reference, because SiO2 is known to be an "inert" support. Additional information on the interaction of Pd/MoO3 catalysts with hydrogen is provided by the microcalorimetric measurements. The impregnation of MoO3 with palladium acetate followed by hydrogen reduction (250 °C) produces Pd/MoO3 catalysts containing Pd particles ca. 8-10 nm, regardless of the metal loading. The XRD, XPS, SEM, TEM, and HRTEM techniques have been employed to characterize the catalysts. The metal particles are nearly monodispersed and well distributed at low Pd-loading, 0.5%Pd/MoO3. As the content of Pd increases the agglomeration of Pd particles occurs. All the Pd/MoO3 catalysts display higher selectivity to C=O hydrogenation compared to Pd/SiO2. The content of Pd has an impact on activity and selectivity. The activity normalized to the Pd mass decreases with growing Pd-loading in Pd/MoO3. The C=C group of CAL was preferentially hydrogenated compared to the carbonyl (C=O) group at low (0.5%Pd) and high (4%Pd) Pd content pointing out to an effect of optimum Pd-loading in the selectivity of CAL hydrogenation. The activity/selectivity behavior of Pd/MoO3 catalysts is related to an effect of hydrogen bronzes existing during the catalytic tests. They could provide additional active sites efficient for the activation of CAL resulting in promotion of C=C hydrogenation. Hydrogen species in the bronzes could also have a beneficial effect on palladium crystallites formation upon reduction of palladium ions. High mobility of hydrogen species in the bronzes structure assisted by easy migration of palladium ions facilitated by MoO3 layered morphology and structural changes during the reduction could promote the Pd crystallites of tetrahedral shape. © 2016 Elsevier B.V. All rights reserved.


Majda D.,Jagiellonian University | Zimowska M.,Jerzy Haber Institute of Catalysis and Surface Chemistry | Tarach K.,Jagiellonian University | Gora-Marek K.,Jagiellonian University | And 2 more authors.
Journal of Thermal Analysis and Calorimetry | Year: 2016

Water thermoporosimetry (TPM) is a powerful method for studying the properties of porous materials, devoted especially for investigation of the samples that can be destroyed in drying process. However, this method is not very popular and relatively rarely used because of problems with proper measurement procedure and choosing correct equation for the result interpretation. This report focused on refinement of general experimental protocols for water TPM. For the first time, the role of various parameters on the TPM outcomes was deeply investigated and simple and fast experimental mode was proposed. Additionally, based on the series of mesoporous silica SBA-15, the calibration procedure was employed and the reliable calibration equations were established. © 2016 The Author(s)

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