MIICr2O4-spinels as supports for Au nanoparticles in oxidation of CO

Ruszel, M.; Grzybowska, B.; Samson, K.; Gressel, I.; Klisińska, A.

doi:10.1016/j.cattod.2005.11.055

Cited by 20 publications

(11 citation statements)

References 10 publications

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“…These findings indicate the role of the support in the creation of the catalytic performance of Au nanoparticles/oxide support systems in CO oxidation. The higher reducibility suggests the presence of higher concentration of the surface oxygen vacancies, which can be the centres of the oxygen activation, as previously proposed [27]. It suggests that CO oxidation over Au/CeO 2 and Au/Ce 0.75 Zr 0.25 O 2 catalysts occurs by the reaction between CO adsorbed mostly on Au nanoparticles and oxygen that can be adsorbed and activated on the oxygen vacancies of the support surface.…”

Section: Characterization Of Catalystsmentioning

confidence: 53%

“…It should be also noticed that the observed increase in activity was relatively stable in time (no deactivation after a few hours of reaction), independently on the applied reduction temperature. Such effect could be related to the reduction (''cleaning'') of oxide species on the surface of the Au particles rather than to the reduction of the support, as previously proposed by Ruszel et al [27]. However, only partial pre-reduction of Au 3?…”

Section: Effect Of Pretreatmentmentioning

confidence: 79%

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Carbon Monoxide Oxidation over Au/Ce1−x Zr x O2 Catalysts: Effects of Moisture Content in the Reactant Gas and Catalyst Pretreatment

2008

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The Au/Ce 1-x Zr x O 2 (x = 0, 0.25, 1) catalysts were synthesized, characterized by BET, XRD, TPR-H 2 , HRTEM, AAS and tested in CO oxidation. The effect of moisture in the reactant gas on CO conversion has been studied in a wide range of concentrations (*0.7-6000 ppm). Moisture generates a positive effect on catalytic activity and wet conditions gave higher CO conversions. The optimum concentration of moisture for CO oxidation over Au/CeO 2 and Au/Ce 0.75 Zr 0.25 O 2 is 200-1000 ppm, while further increase in the moisture content suppresses CO conversion. The activity of the studied Au catalysts depends on the amount of moisture adsorbed on the catalyst rather than on its content in the feed stream, which suggests that the reaction involves water-derived species on the catalysts surface. The effect of the catalysts pretreatment in air, dry He, H 2 stream as well as H 2 ? H 2 O gas mixture on their catalytic performance in CO oxidation has been also investigated. The model of the active sites for CO oxidation over the studied catalysts was proposed.

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Section: Characterization Of Catalystsmentioning

confidence: 53%

Section: Effect Of Pretreatmentmentioning

confidence: 79%

Carbon Monoxide Oxidation over Au/Ce1−x Zr x O2 Catalysts: Effects of Moisture Content in the Reactant Gas and Catalyst Pretreatment

2008

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“…Besides the high activity of the catalysts containing these supports, they provide interesting objects of fundamental studies: the supports possess the same spinel structure and similar specific surface area; they differ, however, depending on cation M II , in physicochemical properties, in particular, reducibility. A correlation between the activity in the CO reactions and the reducibility of these catalysts was indeed observed in [13].…”

Section: Introductionmentioning

confidence: 74%

“…Recently, we have shown that chromites of transition metals, M II Cr 2 O 4 (M II = Co, Mn, Fe, Cu, Mg) can be promising supports for gold catalysts in the oxidation and selective (PROX) oxidation of CO [13]. Besides the high activity of the catalysts containing these supports, they provide interesting objects of fundamental studies: the supports possess the same spinel structure and similar specific surface area; they differ, however, depending on cation M II , in physicochemical properties, in particular, reducibility.…”

Section: Introductionmentioning

confidence: 99%

Au/MCr2O4 (M = Co, Mn, Fe) catalysts in the oxidations of CO, C2, and C3 hydrocarbons

Grzybowska-S̈wierkosz

Ruszel

Grabowski

et al. 2011

Reac Kinet Mech Cat

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Au/M II Cr 2 O 4 (M II = Co, Mn, Fe) catalysts have been tested in the total oxidation of ethane, propane, propene at 300°C and of CO at 35°C, and characterized by TEM, XPS and hydrogen thermo-programmed reduction (H 2 TPR). The catalytic activity has been found to depend on the nature of the oxidized compound. For the CO and ethane oxidation, the activity decreases in the sequence Au/ CoCr 2 O 4 [ Au/MnCr 2 O 4 ) Au/FeCr 2 O 4 and follows the sequence of the decreasing reducibility of the supports and the catalysts, estimated from H 2 TPR measurements. The activity decreases with the increasing Au particle size in the same order, the reactions then seem structure sensitive. No correlations between the activity and reducibility or the particle size are observed for oxidation of the C 3 hydrocarbons: the sequence of the activity for propane is: Au/FeCr 2 O 4 [ Au/CoCr 2 O 4 [ Au/MnCr 2 O 4 , whereas activity in propene oxidation does not change markedly within the studied catalysts. The reaction mechanism in the oxidation of propane and propene seems then to be different from that of oxidation of CO and ethane.The paper is dedicated to the memory of Dr Monica Caldararu, with whom we shared for over 30 years a common interest in oxide catalysis. I enjoyed discussions with Monica and always admired her knowledge, enthusiasm, dynamism and strong will, which helped her to live and work in hard periods of our history and which were highly appreciated by her friends (BGŚ ).

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“…(MCM-48 [17] and SBA-15 [18]). Recently, much interest has been devoted to mixed systems, mostly binary oxide systems such as V 2 O 5 -SiO 2 [19], MoO 3 -SiO 2 [19], Ce 1 -x Zr x O 2 [20], MO x -CeO 2 (M = Mn, Fe, Co, Ni) [21], Au/TiO 2 /Al 2 O 3 [22] and spinelstructure supports M II Cr 2 O 4 (M = Co, Mn, Fe) [23]. These new supports show properties different from those of single oxides.…”

Section: Introductionmentioning

confidence: 99%

Effect of MgO content in the support of Au/MgF2–MgO catalysts on CO oxidation

Tomska-Foralewska

Przystajko

Pietrowski

et al. 2010

Reac Kinet Mech Cat

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Novel magnesium oxo-fluoride supports containing different amounts of MgO, prepared by the sol-gel method have been proposed for the synthesis of gold catalysts. The MgF 2 -MgO supports have mesoporous structure and their surface area is a few times larger than those of pure MgF 2 or pure MgO. Gold catalysts have been prepared by impregnation of the MgF 2 -MgO supports with HAuCl 4 in the amount corresponding to 1 wt.% Au. The gold catalysts has been characterized by XRD, TEM measurements and the catalytic activity in CO oxidation at temperatures 30-300°C have been performed. The Au/MgF 2 -MgO catalysts show higher activities (depending on the content of MgO in the support) as compared to Au/ MgF 2 and Au/MgO prepared under the same conditions. Their activities fall into the upper range of gold catalysts supported on other carrier reported in literature.

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MIICr2O4-spinels as supports for Au nanoparticles in oxidation of CO

Cited by 20 publications

References 10 publications

Carbon Monoxide Oxidation over Au/Ce1−x Zr x O2 Catalysts: Effects of Moisture Content in the Reactant Gas and Catalyst Pretreatment

Carbon Monoxide Oxidation over Au/Ce1−x Zr x O2 Catalysts: Effects of Moisture Content in the Reactant Gas and Catalyst Pretreatment

Au/MCr2O4 (M = Co, Mn, Fe) catalysts in the oxidations of CO, C2, and C3 hydrocarbons

Effect of MgO content in the support of Au/MgF2–MgO catalysts on CO oxidation

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