Engineering Pt in Ceria for a Maximum Metal−Support Interaction in Catalysis

Yeung, Connie M. Y.; Yu, Kai; Fu, Qi; Thompsett, David; Petch, M.I.; Tsang, Shik Chi Edman

doi:10.1021/ja056102c

Cited by 218 publications

(151 citation statements)

References 9 publications

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“…Interestingly, the side reaction of methanation was inhibited even at 773 K, whereas the side reaction of methanation for the impregnated catalysts reached 11.3% at 773 K. It should be noted that X CO of Pt@Ce 0.67 Zr 0.33 O 2 was a little lower in pure syngas than that of Pt@CeO 2 between 573 K and 773 K, but a little higher in sour syngas. Our results were similar to the results reported by Yeung et al [9]. The X CO of 5% Pt@CeO 2 in our work was 69.8% under the conditions of GHSV = 30000 h − 1 , H 2 O/CO = 4.0 at 673 K, and that was 62.5% for 5% Pt@CeO 2 catalyst in the work of Yeung et al [9] under the conditions of the GHSV = 108000 h smaller than that of Pt@CeO 2 .…”

Section: The Wgs Activity Of the Core-shell Catalyst In Pure And Soursupporting

confidence: 92%

“…On the other hand, the catalytic active sites were encapsulated in the porous shell structure, which could prevent the sintering of nanoparticles during the reaction process [7,8]. Recently, some core-shell structured catalysts were studied for the WGS reaction [9,10]. Yeung et al [9] reported a novel coreshell Pt ceria catalyst (Pt@CeO 2 ) prepared by microemulsion method for the WGS reaction.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, some core-shell structured catalysts were studied for the WGS reaction [9,10]. Yeung et al [9] reported a novel coreshell Pt ceria catalyst (Pt@CeO 2 ) prepared by microemulsion method for the WGS reaction. The Pt@CeO 2 catalyst showed similar WGS activity as compared to the common impregnated Pt/CeO 2 catalyst above 673 K, while the side reaction of methanation was inhibited even at 773 K. Wieder et al [10] prepared a 1% Pd@9% CeO 2 /Al 2 O 3 core-shell catalyst by sol-gel method, and studied it for the WGS reaction.…”

Section: Introductionmentioning

confidence: 99%

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Platinum based core–shell catalysts for sour water–gas shift reaction

Liu

Zhang

2012

Catalysis Communications

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Section: The Wgs Activity Of the Core-shell Catalyst In Pure And Soursupporting

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Platinum based core–shell catalysts for sour water–gas shift reaction

Liu

Zhang

2012

Catalysis Communications

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“…10, 2011 The use of ceria-based catalysts has been well established for a variety of environmental applications, such as oxidation of diesel soot, 10 hydrodesulfurization of fossil diesel oil, 1 low temperature naphthalene and CO oxidation, [11][12][13] H 2 S adsorption, 14 water gas shift process 15 and construction of hydrogen fuel cells. 16 These applications, especially the oxidation processes, are related to oxygen storage capacity (OSC), which reflects the ability of ceria to release oxygen upon reduction of Ce IV and to adsorb oxygen upon the oxidation of Ce III , completing a redox cycle and allowing the in situ regeneration of the catalyst by gas flow. 17 The incorporation of cerium species into zeolites has resulted in materials that combine the high activity of ceria with the high surface area and selectivity of zeolites.…”

Section: Introductionmentioning

confidence: 99%

Effect of cerium loading on structure and morphology of modified Ce-USY zeolites

Garcia¹,

Araújo²,

Silva³

et al. 2011

J. Braz. Chem. Soc.

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Este trabalho descreve detalhadamente o efeito da quantidade de cério na estrutura e morfologia da zeólita NH 4 USY. Ce-USY (2-25% m/m de CeO 2 ) foi obtido por impregnação úmida de CeCl 3 seguida de calcinação a 550 ºC por 8 h. Em quantidades baixas (2-10%), foi observado que as espécies de cério encontram-se nas posições de troca iônica na rede, enquanto em maiores teores (15-25%) pequenos agregados formaram-se na superfície da HUSY. Difratometria de raios X (XRD) mostrou apenas reflexões relacionadas à HUSY, confirmando a alta dispersão das espécies de cério, porém as análises por espectroscopia Raman com transformada de Fourier (FT-Raman) detectaram CeO x para os materiais acima de 10%. A reação do CeCl 3 com NH 4 USY produziu NH 4 Cl, o qual se decompõe em HCl, ocasionando a desaluminização da rede. Os materiais apresentaram um aumento da razão Lewis/Brønsted com o aumento da quantidade de cério, devido a interação do excesso de cério com os grupos OH da USY e consequente formação de espécies CeO x . This work describes comprehensibly the effect of cerium loading on the structure and morphology of NH 4 USY zeolite. The Ce-USY (2-25 wt.% of CeO 2 ) was obtained by wet impregnation of CeCl 3 followed by calcination at 550 ºC for 8 h. At low loadings (2-10%), cerium species are mainly located at ion exchange positions in the framework, whereas at higher loadings (15-25%), small aggregates were formed on the HUSY surface. X-ray diffractograms (XRD) exhibited only the reflections related to HUSY, demonstrating the high dispersion of cerium species, but Fourier transform Raman spectroscopy (FT-Raman) detected CeO x for the materials above 10%. Reaction of CeCl 3 with NH 4 USY produced NH 4 Cl, which decomposed to form HCl, leading to framework dealumination. The materials showed an increased Lewis/Brønsted ratio with increasing cerium loadings due to the interaction between the excess cerium and the OH groups of USY, and the consequent formation of CeO x species.Keywords: cerium USY zeolite, cerium oxide, ultra stable Y zeolite, solid-state ion exchange, 27 Al and 29 Si MAS NMR spectroscopy IntroductionFaujasite-type zeolites (X and Y) are largely applied in fluid catalytic cracking (FCC) of crude oil distillates and in hydrodesulfurization of fossil diesel oil and gasoline. 1 Y zeolites, either in their sodium or ammonium form, can be exchanged for rare earth ions to achieve the following main goals: (i) to prevent aluminum loss from the zeolite structure, which results in enhanced structural resistance to the severe hydrothermal conditions of the regeneration step of FCC, 2 and (ii) to increase the activity, because the introduction of rare earth species modifies the number of acidic protons through either hydrolysis or enhancement of ionic fields inside the zeolite structure. 3 Because rare earth cations modify the acidic properties of zeolites, their insertion has an effect on both thermal and mechanical stability, which are important for zeolite application to industrial processes such as pyrolysis, 4 oxidat...

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“…1 Further industrial applications arise from a wide range of favorable properties, particularly resistance to chemical corrosion over a wide temperature range, high melting point, high mechanical strength and good ductility. Platinum is also used in jewelry and dentistry.…”

Section: Introductionmentioning

confidence: 99%

Spectrophotometric Determination of Traces of Platinum with 5-Chloro-2-hydroxythiobenzhydrazide after Extraction into Molten Naphthalene

Sawant

2010

ANAL. SCI.

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Platinum(IV) can be determined spectrophotometrically with 5-chloro-2-hydroxythiobenzhydrazide on extraction into molten naphthalene from the aqueous phase with pH 2.2 -6.0. Beer's law is obeyed in the concentration range 1.0 -7.0 μg cm -2 of Pt(IV) in 4-methyl-2-pentanone solution at 680 nm. The molar absorptivity and Sandell sensitivity are found to be 2.40 × 10 4 L mol -1 cm -1 and 8.0 ng cm -2 , respectively. Six replicate analyses of a solution containing 40.0 μg of Pt(IV) gave a mean absorbance of 0.505 with a standard deviation of 0.0065 and a coefficient of variation of 1.30%. The complex is stable for more than 48 h. The metal to ligand ratio in the complex is determined to be 1:1. Interference from various ions is studied and the method is found to be selective for platinum. Platinum is determined in various synthetic mixtures and in some alloy samples. The method permits the sequential separation and determination of different amounts of platinum and rhenium from their mixtures.

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Engineering Pt in Ceria for a Maximum Metal−Support Interaction in Catalysis

Cited by 218 publications

References 9 publications

Platinum based core–shell catalysts for sour water–gas shift reaction

Platinum based core–shell catalysts for sour water–gas shift reaction

Effect of cerium loading on structure and morphology of modified Ce-USY zeolites

Spectrophotometric Determination of Traces of Platinum with 5-Chloro-2-hydroxythiobenzhydrazide after Extraction into Molten Naphthalene

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