Characterization of carbon supported palladium catalysts: inference of electronic and particle size effects using reaction probes

Ramos, André Luís Dantas; Alves, Péricles da Silva; Aranda, Donato Alexandre Gomes; Schmal, Martín

doi:10.1016/j.apcata.2004.08.033

Cited by 121 publications

(28 citation statements)

References 42 publications

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“…This profile also shows an inverted peak at 339 K which could be assigned to the decomposition of the b-PdH phase. 12,21,29,32,34 This proves that at the reduction temperature adopted for the PdAl catalyst (573 K) the palladium b-hydride phase was eliminated.…”

Section: Resultsmentioning

confidence: 80%

“…27 As it can be seen in Table 1 the XPS results for the palladium monometallic catalyst treated in hydrogen at 573 K show that the Pd 3d 5/2 signal is located at 334.9 eV; according to the literature, it can be assigned to Pd°. 24,28,29 For the nickel monometallic catalyst reduced at 673 K, the BE for Ni 2p 3/2 was 853.5 eV, which can be assigned to electro-defficient nickel species (Ni n+ ), probably corresponding to nickel interacting with aluminum. 30 The BE of the Pd 3d 5/2 signal in the bimetallic catalyst increases with the nickel content: 335.6 and 335.9 eV for 0.5 and 1.0 Ni wt %, respectively (see in Table 1).…”

Section: Resultsmentioning

confidence: 99%

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Influence of ni addition to a low-loaded palladium catalyst on the selective hydrogenation of 1-heptyne

et al. 2010

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Recebido em 27/4/09; aceito em 30/10/09; publicado na web em 12/3/10 Semi-hydrogenation of alkynes has industrial and academic relevance on a large scale. To increase the activity, selectivity and lifetime of monometallic catalysts, the development of bimetallic catalysts has been investigated. 1-Heptyne hydrogenation over low-loaded Pd and Ni monometallic and PdNi bimetallic catalysts was studied in liquid phase at mild conditions. XPS results suggest that nickel addition to Pd modifies the electronic state of palladium as nickel loading is increased. Low-loaded Pd catalysts showed the highest selectivities (> 95%). The most active prepared catalyst, PdNi (1%) , was more selective than the Lindlar catalyst.

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Section: Resultsmentioning

confidence: 80%

Section: Resultsmentioning

confidence: 99%

Influence of ni addition to a low-loaded palladium catalyst on the selective hydrogenation of 1-heptyne

et al. 2010

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“…The TPR trace of the Pd monometallic catalyst had a main hydrogen consumption peak at 287 K, which can be attributed to the reduction of PdO species and to the formation of palladium hydrides [29]. This catalyst also has an inverted reduction peak at 339 K that could be related to the decomposition of thePdH phase [20,21,24]. As these species interact weakly with the support the palladium hydrides are completely eliminated during reduction.…”

Section: Counts/smentioning

confidence: 96%

“…The XRD difractograms of the catalysts only present the -alumina peaks at 2θ = 37.7, 46.0 and 67.0º [24][25][26]. For this reason the difractograms are not shown.…”

Section: Counts/smentioning

confidence: 99%

Kinetic Study of the Partial Hydrogenation of 1-Heptyne over Ni and Pd Supported on Alumina

Maccarrone¹,

Torres²,

Lederhos³

et al. 2012

Hydrogenation

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“…[11][12][13] Several papers have mentioned the relationship between particle size and reaction activity or selectivity. [14][15][16][17][18][19][20] Catalytic dependence on surface structure in practical applications has different features. Vol.…”

Section: Introductionmentioning

confidence: 99%

Effect of Metal Dispersion on the Hydrogenation of 2-Amyl Anthraquinone over Pd/Al₂O₃Catalyst

Li¹,

Su²,

Ren³

et al. 2016

Journal of the Brazilian Chemical Society

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A series of highly dispersed Pd/Al 2 O 3 catalysts were prepared via the polyol method. The catalysts were characterized by nitrogen adsorption, X-ray diffraction (XRD), UV-Vis spectrophotometry, temperature programmed reduction (TPR) and transmission electron microscopy (TEM). The influence of Pd particle size on the hydrogenation of 2-amyl anthraquinone (AAQ) was investigated in a trickle-bed reactor. The turnover frequency (TOF) showed antipathetic size dependence while the space time yield (STY) peaked at 4 nm. Also, the selectivity and deactivation rate were affected by the size of palladium particles. The structure-sensitivity relations for the catalysts may be ascribed to the necessities of specific Pd cluster structure for the activation of π-bond. Keywords: anthraquinone hydrogenation, H 2 O 2 , dispersion IntroductionHydrogen peroxide (H 2 O 2 ) is widely used in the chemical industry and environmental protection as an environmentally friendly oxidant. [1][2][3] Today, hydrogen peroxide is manufactured almost exclusively by the autoxidation of 2-alkyl anthrahydroquinone (2-alkyl AQH 2 ) to the corresponding 2-alkyl anthraquinone (2-alkyl AQ) in the so-called AQ process. In the cyclic process, AQ is hydrogenated to yield anthrahydroquinone, then oxidation of the latter produces hydrogen peroxide and regenerates the starting AQ (Scheme 1). 4 Major producers commonly use either the 2-ethyl or the 2-amyl derivative of AQ. In recent years, along with the production growth of downstream products such as propylene oxide and caprolactam, the market demand for H 2 O 2 solution at high concentration has been increasing substantially. Given its high solubility, 2-amylanthraquinone is considered as a good replacement for the widely used 2-ethylanthraquinone to increase productivity. 5 The network of the reactions taking place during the hydrogenation of 2-amyl anthraquinone (AAQ) is quite complicated. The desired products considered as active anthraquinones are 2-amyl anthrahydroquinone (AAQH 2 ) and 2-amyl tetrahydroanthrahydroquinone (H 4 AAQH 2 ), which could produce H 2 O 2 after oxidation. However, other degradations such as 2-amyl octahydroanthrahydroquinone (H 8 AAQH 2 ) and anthrone (AN) are useless to the H 2 O 2 production.6 Previous literature about the hydrogenation of anthraquinone used the 2-ethyl-anthraquinone (EAQ) system rather than the 2-amylanthraquinone system. In addition, the research focused on the topics such as the enhancement of mass transfer and the properties of support. For example, Santacesaria et al. 7 reported that the hydrogenation of 2-ethyl-anthraquinone over Pd catalysts was a fast reaction and the mass transfer of EAQ was the rate limiting step. Based on this, Luo and co-workers 8 designed an egg shell Pd/glass catalyst which can achieve a high instant yield of H 2 O 2 of 11.2 g L -1. Besides, the acid-base property of the support was a key point to influence the catalyst activity and selectivity, as the acid sites of the support were considered as the adsorption sites of EAQ...

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Characterization of carbon supported palladium catalysts: inference of electronic and particle size effects using reaction probes

Cited by 121 publications

References 42 publications

Influence of ni addition to a low-loaded palladium catalyst on the selective hydrogenation of 1-heptyne

Influence of ni addition to a low-loaded palladium catalyst on the selective hydrogenation of 1-heptyne

Kinetic Study of the Partial Hydrogenation of 1-Heptyne over Ni and Pd Supported on Alumina

Effect of Metal Dispersion on the Hydrogenation of 2-Amyl Anthraquinone over Pd/Al₂O₃Catalyst

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Characterization of carbon supported palladium catalysts: inference of electronic and particle size effects using reaction probes

Cited by 121 publications

References 42 publications

Influence of ni addition to a low-loaded palladium catalyst on the selective hydrogenation of 1-heptyne

Influence of ni addition to a low-loaded palladium catalyst on the selective hydrogenation of 1-heptyne

Kinetic Study of the Partial Hydrogenation of 1-Heptyne over Ni and Pd Supported on Alumina

Effect of Metal Dispersion on the Hydrogenation of 2-Amyl Anthraquinone over Pd/Al2O3Catalyst

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Effect of Metal Dispersion on the Hydrogenation of 2-Amyl Anthraquinone over Pd/Al₂O₃Catalyst