Role of ethylenediamine in the preparation of alumina-supported Ni catalysts from [Ni(en)2(H2O)2](NO3)2: from solution properties to nickel particles

Négrier, Fabien; Marceau, Éric; Che, Michel; de, Dominique

doi:10.1016/s1631-0748(03)00026-2

Cited by 44 publications

(55 citation statements)

References 29 publications

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“…Another reduction peak is observed at 450 °C which could be attributed to Pdalumina support interactions and a strong support de-hydroxylation. The TPR profile was similar to those reported by Garcia et al [20] for Pd supported on alumina catalysts. On the other hand, the TPR profile of the bimetallic Ni-Pd/Al2O3 is very similar to those corresponding to the monometallic Pd.…”

Section: Bulletin Of Chemical Reaction Engineering and Catalysis 11 (2supporting

confidence: 88%

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Thermo-Catalytic Methane Decomposition for Hydrogen Production: Effect of Palladium Promoter on Ni-based Catalysts

Mei

Lock

et al. 2016

Bull. Chem. React. Eng. Catal.

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Hydrogen production from the direct thermo-catalytic decomposition of methane is a promising alternative for clean fuel production. However, thermal decomposition of methane can hardly be of any practical and empirical interest in the industry unless highly efficient and effective catalysts, in terms of both catalytic activity and operational lifetime have been developed. In this study, the effect of palladium (Pd) as a promoter onto Ni supported on alumina catalyst has been investigated by using coprecipitation technique. The introduction of Pd promotes better catalytic activity, operational lifetime and thermal stability of the catalyst. As expected, highest methane conversion was achieved at reaction temperature of 800 °C while the bimetallic catalyst (1 wt.% Ni -1 wt.% Pd/Al2O3) gave the highest methane conversion of 70% over 15 min of time-on-stream (TOS). Interestingly, the introduction of Pd as promoter onto Ni-based catalyst also has a positive effect on the operational lifetime and thermal stability of the catalyst as the methane conversion has improved significantly over 240 min of TOS.

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Section: Bulletin Of Chemical Reaction Engineering and Catalysis 11 (2supporting

confidence: 88%

“…The higher temperature reduction peak may be attributed to the strong interaction of spinel NiAl2O4 phase. The formation of a [18][19][20]. For the Pd/Al2O3 catalyst, the TPR traces exhibited a main hydrogen consumption peak due to the reduction of PdO species to metallic palladium.…”

Section: Bulletin Of Chemical Reaction Engineering and Catalysis 11 (2mentioning

confidence: 99%

Thermo-Catalytic Methane Decomposition for Hydrogen Production: Effect of Palladium Promoter on Ni-based Catalysts

Mei

Lock

et al. 2016

Bull. Chem. React. Eng. Catal.

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“…The mass loss around 350°C (stage C) can be due to decomposition of carbon remains along with evolution of hydrogen [19]. The mass increase between 400 and 550°C (stage D) is due to nickel oxidation.…”

Section: Thermolysis Experimentsmentioning

confidence: 99%

Oxidation kinetics of nickel nano crystallites obtained by controlled thermolysis of diaquabis(ethylenediamine)nickel(II) nitrate

Robinson

Arun

Manju

et al. 2009

J Therm Anal Calorim

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The metal complex, [Ni(en) 2 (H 2 O) 2 ](NO 3 ) 2 (en = ethylenediamine), was decomposed in a static furnace at 200°C by autogenous decomposition to obtain phase pure metallic nickel nanocrystallites. The nickel metal thus obtained was studied by XRD, IR spectra, SEM and CHN analysis. The nickel crystallites are in the nanometer range as indicated by XRD studies. The IR spectral studies and CHN analyses show that the surface is covered with a nitrogen containing species. Thermogravimetric mass gain shows that the product purity is high (93%). The formed nickel is stable and resistant to oxidation up to 350°C probably due to the coverage of nitrogen containing species. Activation energy for the oxidation of the prepared nickel nanocrystallites was determined by non-isothermal methods and was found to depend on the conversion ratio. The oxidation kinetics of the nickel crystallites obeyed a Johnson-Mehl-Avrami mechanism probably due to the special morphology and crystallite strain present on the metal.

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“…19,21,24 In particular, the effect of en on Ni catalysts have been studied in detail by Che et al using support powders. 18,19,[25][26][27][28] However, very few studies have been done on the effect of chelating ligands in the preparation of catalyst bodies. 15c,29 In this paper, the influence of the number of en ligands on the macrodistribution and molecular speciation of Ni 2+ in γ-Al 2 O 3 catalyst bodies during impregnation and drying has been investigated.…”

Section: Introductionmentioning

confidence: 99%

Effect of the Nickel Precursor on the Impregnation and Drying of γ-Al₂O₃ Catalyst Bodies: A UV−vis and IR Microspectroscopic Study

2008

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The elemental preparation steps of impregnation and drying of Ni/γ-Al 2 O 3 catalyst bodies have been studied by combining UV-vis and IR microspectroscopy. The influence of the number of chelating ligands in [Ni(en) 2+ precursor complexes (with en ) ethylenediamine and x ) 0-3) has been investigated. UV-vis measurements after impregnation showed that, regardless of the en:Ni 2+ ratio in the precursor solution, Ni 2+ was already detected in the core of the pellets 5 min after impregnation. The alumina support did bring about, however, gradients in the nature of the Ni 2+ species upon first contact with the lowest en:Ni 2+ ratio solutions, but these gradients disappeared after 30-60 min of impregnation. After 60 min, UV-vis seemed to indicate Ni-O-Al interactions between Ni 2+ and the support, when water was initially part of the first coordination sphere of Ni 2+ , which was supported with the results obtained after drying. For dried samples, UV-vis showed a gradient of [Ni(en) x (H 2 O) 6-2x ] 2+ inside the pellets, with an en-poor region in the core and an en-rich region in the edges of the catalyst bodies, when [Ni(en) were the starting complexes. IR microspectroscopy confirmed these en radial profiles, while EDX measurements showed that an Ni 2+ egg-shell distribution goes hand-in-hand with an egg-shell distribution of en. The number of en ligands determined the interactions of Ni 2+ with the support after impregnation and controlled the redistribution of metal-ion species during drying. Moreover, when redistribution of Ni 2+ occurred during drying, its transport toward the outer rim of the extrudates came about together with changes of the local en:Ni 2+ ratio.

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Role of ethylenediamine in the preparation of alumina-supported Ni catalysts from [Ni(en)2(H2O)2](NO3)2: from solution properties to nickel particles

Cited by 44 publications

References 29 publications

Thermo-Catalytic Methane Decomposition for Hydrogen Production: Effect of Palladium Promoter on Ni-based Catalysts

Thermo-Catalytic Methane Decomposition for Hydrogen Production: Effect of Palladium Promoter on Ni-based Catalysts

Oxidation kinetics of nickel nano crystallites obtained by controlled thermolysis of diaquabis(ethylenediamine)nickel(II) nitrate

Effect of the Nickel Precursor on the Impregnation and Drying of γ-Al₂O₃ Catalyst Bodies: A UV−vis and IR Microspectroscopic Study

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Role of ethylenediamine in the preparation of alumina-supported Ni catalysts from [Ni(en)2(H2O)2](NO3)2: from solution properties to nickel particles

Cited by 44 publications

References 29 publications

Thermo-Catalytic Methane Decomposition for Hydrogen Production: Effect of Palladium Promoter on Ni-based Catalysts

Thermo-Catalytic Methane Decomposition for Hydrogen Production: Effect of Palladium Promoter on Ni-based Catalysts

Oxidation kinetics of nickel nano crystallites obtained by controlled thermolysis of diaquabis(ethylenediamine)nickel(II) nitrate

Effect of the Nickel Precursor on the Impregnation and Drying of γ-Al2O3 Catalyst Bodies: A UV−vis and IR Microspectroscopic Study

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Effect of the Nickel Precursor on the Impregnation and Drying of γ-Al₂O₃ Catalyst Bodies: A UV−vis and IR Microspectroscopic Study