Nickel-based catalysts: Dependence of properties on nickel loading and modification with palladium

Nikolić, D.; Kamberovic, J Zeljko; Korać, Marija; Andjic, Z.; Mihajlovic, Maja; Uljarevic, B Jelena

doi:10.2298/hemind140928090n

Cited by 5 publications

(5 citation statements)

References 22 publications

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“…Modifying the Ni catalyst with Pd lowered the catalyst reduction temperature, as evidenced by CO-adsorbed FTIR and CO chemisorption, in agreement with the literature [70]. Additionally, during the reaction in a reductive atmosphere, the reduction of Ni can be favored by a spillover effect taking place on the surface Pd, on which H 2 molecules dissociate into atomic hydrogen.…”

Section: Discussionsupporting

confidence: 87%

“…Additionally, during the reaction in a reductive atmosphere, the reduction of Ni can be favored by a spillover effect taking place on the surface Pd, on which H 2 molecules dissociate into atomic hydrogen. The stronger reducing power of atomic hydrogen compared to molecular gaseous H 2 is consequently beneficial for the hydrogenation reactions, while it can also favor an easier reduction of surface NiO x species after fast diffusion into the Ni crystal lattice [21,70].…”

Section: Discussionmentioning

confidence: 99%

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Ni-Pd/γ-Al2O3 Catalysts in the Hydrogenation of Levulinic Acid and Hydroxymethylfurfural towards Value Added Chemicals

et al. 2020

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γ-Al2O3 supported Ni-Pd catalysts with different Ni:Pd ratios were studied in the hydrogenation of two industrially-relevant platform molecules derived from biomass, namely levulinic acid and hydroxymethylfurfural. The bimetallic catalysts showed better performances in both processes in comparison to the monometallic counterparts, for which a too strong interaction with the alumina support reduced the activity. The behavior of the bimetallic catalysts was dependent on the Ni:Pd ratio, and interestingly also on the targeted hydrogenation reaction. The Pd-modified Ni-rich system behaves like pure Ni catalyst, but with a strongly boosted activity due to a higher number of Ni active sites available, Pd being considered as a spectator. This high activity was manifested in the levulinic acid hydrogenation with formic acid used as an internal hydrogen source. This behavior differs from the case of the Pd-rich system modified by Ni, which displayed a much higher Pd dispersion on the support compared to the monometallic Pd catalyst. The higher availability of the Pd active sites while maintaining a high surface acidity allows the catalyst to push the HMF hydrodeoxygenation reaction forward towards the green biopolymer precursor 2,5-bis(hydroxymethyl)-tetrahydrofuran, and in consequence to strongly modify the selectivity of the reaction. In that case, residual chlorine was proposed to play a significant role, while Ni was considered as a spectator.

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Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 99%

Ni-Pd/γ-Al2O3 Catalysts in the Hydrogenation of Levulinic Acid and Hydroxymethylfurfural towards Value Added Chemicals

et al. 2020

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“…22-118) was observed and via the following reaction and calcination at temperatures above 700 ºC, the NiAl2O4 formed as Equation ( 5). Calcination causes formation of NiAl2O4 spinel phase, especially in the case of Al2O3 (γ) presence [47].…”

Section: Resultsmentioning

confidence: 99%

NiO-Ni-Al2O3(γ) Nanocatalyst by Pulse Electrocodeposition Over Ni Open-cell Foam for Methane Reforming

Zafardoagoo,

Sadrnezhaad,

Mostaghimi

2023

IJE

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Global warming persuades researchers to improve the effectiveness of renewable energy technologies, such as H2 production by methane steam reforming (MSR) an endothermic process. Herein, a nanocatalyst based on open-cell nickel foam 40 (pore per inch) with high thermal conductivity was prepared. The nanocatalyst was synthesized with a chemical stepwise synthesis approach, chemical pretreatment, pulsed electrocodeposition of Ni-Al2O3(γ) nanoparticles, and calcination. Measurements of thermal diffusivity(α) with flash xenon technique gained 4.41×10 -6 m 2 s -1 and values of specific heat capacity, Cp, by differential scanning calorimetry (DSC) and thermal conductivity(λ) enhanced by 65% in temperature range of 150 to 550°C in Ni-alumina(γ) foam nanocatalyst. Furthermore, characterization and tests for comparing nickel foam and Ni-alumina(γ) foam indicated that the hardness improved from 145 Vickers hardness (HV) to 547 HV and compression strength increased from 1.1 MPa to 5MPa and specific surface area (SBET) from 1.48 m 2 g -1 to 48 m 2 g -1 . XRD (x-ray diffraction) analysis showed NiO and NiAl2O4 in the structure. The interface between the catalytic component (NiAl2O4), and nickel affected the catalytic ability for MSR, and the efficiency gained at low tempreture 500 °C was the same as reported at 720°C by other investigations.

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“…Porous ceramics are widely used in adsorption, but also in heterogeneous catalysis to support catalytically active substances for waste gas treatment due to high porosity and permeability to liquids, as well as high thermal stability and low density of these materials [5][6][7][8][9][10][11][12][13]. There are numerous methods for the synthesis of either porous solid shapes or fine particles based on ceramics such as polymer replication [10,14], modified sol-gel method [12,15], sintering of green bodies prepared from starting ceramic powders [14,16], external gelatinization [17], etc.…”

Section: Introductionmentioning

confidence: 99%

Investigating possibilities for synthesis of novel sorbents and catalyst carriers based on ceramics with controlled open porosity

Nikolić¹,

Djokić

Kamberović

et al. 2022

Hem Ind

Self Cite

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The aim of this study was to investigate a possibility of synthesis of porous ceramics with controlled open porosity, which could be used as sorbents and catalyst supports. Two organic additives were used to obtain open porosity: polystyrene beads and cellulose fibers, which are mixed with kaolin clay powder and the appropriate water content. Samples were sintered at 1050?C for 1h. Characterization of the obtained products included X-ray powder diffraction analysis (XRPD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and elemental CHNS analysis. In addition, porosity was examined by quantification of visual information. The specific surface areas were determined by the Brunauer-Emmett-Teller (BET) method. Also, density and compressive strength of the obtained samples were assessed. It was determined that by sintering, the organic component completely leaves the system. For samples prepared with polystyrene beads and with cellulose fibers, satisfactory mechanical properties were obtained: compressive strengths were 1.42 and 1.56 MPa, respectively. It was noted that significantly higher open porosity was obtained by using polystyrene beads as a sacrificial template (porosity of ~56 %) instead of cellulose fibers (porosity of ~6 %).

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Nickel-based catalysts: Dependence of properties on nickel loading and modification with palladium

Cited by 5 publications

References 22 publications

Ni-Pd/γ-Al2O3 Catalysts in the Hydrogenation of Levulinic Acid and Hydroxymethylfurfural towards Value Added Chemicals

Ni-Pd/γ-Al2O3 Catalysts in the Hydrogenation of Levulinic Acid and Hydroxymethylfurfural towards Value Added Chemicals

NiO-Ni-Al2O3(γ) Nanocatalyst by Pulse Electrocodeposition Over Ni Open-cell Foam for Methane Reforming

Investigating possibilities for synthesis of novel sorbents and catalyst carriers based on ceramics with controlled open porosity

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