A series of Ce-Fe mixed oxides as well as the pure oxides were synthesized by the microemulsions method. The solid solution formation was established for all the Fe-doped systems and only a hardly noticeable segregation of α-Fe2O3 was appreciated for the solid with the maximum iron content (50at.% Fe). The oxygen exchange is improved for all...
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December 27, 2017 (v1)PublicationUploaded on: March 27, 2023
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November 12, 2018 (v1)Publication
Gold catalysts were synthesized by deposition-precipitation employing Fe-doped ceria systems, previously obtained by means of the water-in-oil microemulsions methodology with different iron contents (10, 25 and 50 Fe at.%). The final catalysts were tested in the CO oxidation reaction in presence of H2. After gold deposition the crystalline...
Uploaded on: March 27, 2023 -
April 10, 2018 (v1)Publication
Two blocks of microreactors composed by 100 microchannels and coated, respectively, with 150 and 300 mg of a CuOx/CeO2 catalyst, were prepared and tested in the preferential oxidation of CO in presence of H2 (PROX). The deposition of different amount of catalyst resulted in different catalytic layer thicknesses thus modifying the catalytic...
Uploaded on: March 27, 2023 -
March 22, 2018 (v1)Publication
Rh/MnO2-CeO2/Al2O3 catalysts with different manganese-to-ceria ratios have been synthesized, characterized and tested in CO-PrOx reaction. The physicochemical properties of the solids were studied by XRD, Raman spectroscopy, BET surface area, H2-TPR, TGA-DTG and TEM. The differences observed in the textural, structural and redox properties were...
Uploaded on: March 27, 2023 -
December 28, 2017 (v1)Publication
A series of Zn-modified ceria solids were prepared by thermal decomposition of the corresponding metal propionates. The formation of segregated ZnO particles on the ceria surface is evidenced for these solids using X-ray diffraction; in addition to this the characterization data may allow discarding the formation of a ZnO¿CeO2 solid solution....
Uploaded on: December 5, 2022 -
April 5, 2018 (v1)Publication
A series of ceria oxides doped with 10 mol.% of Zr, Zn and Fe have been prepared by a pseudo sol-gel method throughout the thermal decomposition of the corresponding metallic propionates. With these supports, 1 wt.% gold catalysts were prepared by the deposition-precipitation method. All the solids were characterized by means of XRF, N2...
Uploaded on: March 27, 2023 -
April 10, 2018 (v1)Publication
The CO oxidation activity of 1 wt.% gold catalysts prepared by depositionprecipitation on a series of ceria doped with Zr supports was studied. The supports (10, 25 and 50 Zr At. %) were synthesized by a pseudo sol-gel method through the thermal decomposition of the corresponding metallic propionates. All the prepared solids were characterized...
Uploaded on: December 4, 2022 -
February 21, 2019 (v1)Publication
The current scenario where the effects of global warming are more and more evident, has motivated different initiatives for facing this, such as the creation of global policies with a clear environmental guideline. Within these policies, the control of Greenhouse Gase (GHG) emissions has been defined as mandatory, but for carrying out this, a...
Uploaded on: March 27, 2023 -
November 18, 2016 (v1)Publication
In this comprehensive review, the main aspects of using Au/CeO2 catalysts in oxidation reactions are considered. The influence of the preparation methods and synthetic parameters, as well as the characteristics of the ceria support (presence of doping cations, oxygen vacancies concentration, surface area, redox properties, etc.) in the...
Uploaded on: December 4, 2022 -
November 7, 2018 (v1)Publication
A copper-ceria bulk catalyst has been compared to a series of catalysts designed according to the as called "supported approach", corresponding to the dispersion of low content mixed copper-ceria oxide on alumina matrix. The principal characteristics of both types of catalysts are contemplated and the differences in their electronic and redox...
Uploaded on: December 4, 2022 -
September 28, 2022 (v1)Publication
The importance of water availability during the WGS reaction has been extensively reported. Thus, the search of new supports able to interact with the water molecule is of great importance. In this work, a series of phosphate- type supports containing Ce, Ca and Ti have been studied, demonstrating that water interaction with the support is...
Uploaded on: March 24, 2023 -
September 29, 2022 (v1)Publication
Routinely, it seems assumed that the catalytic layer coated on monoliths and microchannel reactors preserve the properties of the initial powder catalyst. However, this assumption should be reasonably demonstrated since the set of chemical and physical manipulations involved in the preparation of these catalytic devices hardly does not alter...
Uploaded on: December 4, 2022 -
April 2, 2018 (v1)PublicationIron-modified ceria and Au/ceria catalysts for Total and Preferential Oxidation of CO (TOX and PROX)
Iron-modified ceria supports containing different molar percentages of Fe (0%, 10%, 25%, and 50%) were synthesized by thermal decomposition of the metal propionates. The formation of a Ce-Fe oxide solid solution is evidenced through XRF, XRD, BET and Raman spectroscopy. For iron contents above 25% the formation of ¿-Fe2O3 was detected, pointing...
Uploaded on: December 2, 2022 -
February 7, 2018 (v1)Publication
Hydrogen produced from the conversion of hydrocarbons or alcohols contains variable amounts of CO that should be removed for some applications such as feeding low-temperature polymer electrolyte membrane fuel cells (PEMFCs). The CO preferential oxidation reaction (PROX) is particularly well-suited for hydrogen purification for portable and...
Uploaded on: March 27, 2023 -
November 16, 2018 (v1)Publication
This work is devoted to the development of novel structured catalytic system for WGS reaction. The new concept is related to the presence of a pre-catalytic "buffer" layer formed by WGS-inert oxide, i.e. not involved in CO conversion, but able to increase the number of participating sites in water dissociation step during the reaction. The...
Uploaded on: March 27, 2023 -
February 19, 2018 (v1)Publication
A computational fluid dynamics (CFD) simulation study of the preferential oxidation of CO (CO-PROX) in microstructured reactors consisting in square and semicircular microchannels coated with anAu/CuOx¿CeO2catalyst is presented. The CO content of the feed stream was set at 1 vol.%. A parametricsensitivity analysis has been performed under...
Uploaded on: March 27, 2023 -
February 7, 2023 (v1)Publication
A series of cobalt-based catalysts have been synthesized using as support γ-Al2O3 promoted by ceria/zirconia mixed oxides with a variable Ce/Zr molar ratio. The obtained catalysts demonstrated oxide promotion results in the protection of the major textural properties, especially for Zr-rich solids. Reducibility of cobalt species was enhanced by...
Uploaded on: February 22, 2023 -
October 20, 2022 (v1)Publication
One of the most remarkable benefits of the microreactors is the achievement of more efficient processes by enhancing the heat and mass transfer phenomena, which is the key factor for processes intensification in chemical reactions, resulting in higher conversion, selectivity and yield towards desired products. Currently, the entire scenario of...
Uploaded on: December 4, 2022 -
July 4, 2019 (v1)Publication
For this present work, a series of Au-metallized TiO 2 catalysts were synthesized and characterized in order to compare their performance in two different catalytic environments: the phenol degradation that occurs during the liquid phase and in the CO oxidation phase, which proceeds the gas phase. The obtained materials were analyzed by...
Uploaded on: March 25, 2023 -
September 5, 2018 (v1)Publication
In the last ten years, there has been an acceleration in the pace at which new catalysts for the watergas shift reaction are designed and synthesized. Pt-based catalysts remain the best solution when only activity is considered. However, cost, operation temperature, and deactivation phenomena are important variables when these catalysts are...
Uploaded on: March 27, 2023 -
July 4, 2019 (v1)Publication
In this study, titanium dioxide powder obtained by the sol-gel method and TiO2nanotubes, were prepared. In order to increase the TiO2 photoactivity, the powders and nanotubes obtained were modified by dye sensitization treatment during the oxide synthesis. The sensitizers applied were Quinizarin (Q) and Zinc protoporphyrin (P). The materials...
Uploaded on: March 27, 2023 -
March 21, 2017 (v1)Publication
Experimental catalytic activity measurements, Diffuse Reflectance Infrared Fourier Spectroscopy, and Density Functional Theory calculations are used to investigate the role and dynamics of surface oxygen vacancies in the CO oxidation with O2 catalyzed by Au nanoparticles supported on a Y-doped TiO2 catalyst. Catalytic activity measurements...
Uploaded on: December 5, 2022 -
March 2, 2018 (v1)Publication
The catalytic performance of a CuOx/CeO2 powder catalyst and that of a microchannel reactor or microreactor (MR) coated with the same solid was determined and compared. The catalytic activity measurements were carried out with varying O2/CO molar ratios in the feed-stream. In addition, the influence of the presence of CO2 and H2O in the...
Uploaded on: December 4, 2022 -
March 5, 2018 (v1)Publication
The general aspects of the synthesis and characterization results of a CuOx/CeO2 catalyst were presented. In addition the principal steps for manufacturing a microchannel reactor and for the coating of the CuOx/CeO2 catalyst onto the microchannels walls, were also summarized. The catalytic activity of this microchannel reactor during the...
Uploaded on: December 4, 2022