Influence of preparation method on dispersion of cobalt spinel over alumina extrudates and the catalyst deN 2 O activity

Grzybek, Gabriela; Wojcik, Sylwia E.; Ciura, Klaudia; Gryboś, Joanna; Indyka, Paulina; Oszajca, Marcin; Stelmachowski, Paweł; Witkowski, Stefan; Inger, Marek; Wilk, Marcin; Kotarba, Andrzej; Sojka, Zbigniew

doi:10.1016/j.apcatb.2017.03.053

Cited by 33 publications

(11 citation statements)

References 37 publications

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“…During this process, the solutes migrate due to capillary flow and diffusion, causing a redistribution of the adsorbed catalytically active species. Finally, calcination and reduction transform the catalyst from its precursor state into its active form [65][66][67][68].…”

Section: Theory/calculationmentioning

confidence: 99%

Synthesis and Mathematical Modelling of the Preparation Process of Nickel-Alumina Catalysts with Egg-Shell Structures for Syngas Production via Reforming of Clean Model Biogas

et al. 2022

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For the work presented herein nickel catalysts supported on γ-alumina extrudates (Ni/Al) with an egg-shell structure were prepared, using a modified Equilibrium Deposition Filtration (EDF) technique. Their performance was compared, for the biogas dry reforming reaction, with corresponding Ni/Al catalysts with a uniform structure, synthesized via the conventional wet impregnation method. The bulk and surface physicochemical characteristics of all final catalysts were determined using ICP-AES, N2 adsorption-desorption isotherms, XRD, SEM, and TEM. A theoretical model describing the impregnation process for the EDF extrudates, based on the Lee and Aris model, was also developed. It was concluded that following specific impregnation conditions, the egg-shell macro-distributions can be successfully predicted, in agreement with the experimental results. It was shown that the Ni/Al catalysts with an egg-shell structure had a higher H2 yield in comparison with the ones with a uniform structure. The difference in catalytic performance was attributed to the improved surface and structural properties of the egg-shell catalysts, resulting from the modified EDF technique used for their preparation.

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Section: Theory/calculationmentioning

confidence: 99%

Synthesis and Mathematical Modelling of the Preparation Process of Nickel-Alumina Catalysts with Egg-Shell Structures for Syngas Production via Reforming of Clean Model Biogas

et al. 2022

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“…In relation, organic media has been effective to control deposition of alike materials as CoO-NP 18 in PS-DVB, functionalization of porous solids with precise nanoscale resolution using individual localized wetting states 19 and, bene cial to impregnate metallic salts in alumina extrudates 15 using glycerol but, when physical a nity is not met at any level, alternative interactions as ones presented here are necessary.…”

Section: Introductionmentioning

confidence: 99%

“…Judicious selection of organic media and nite size of both partners, allows for exquisite ne-tuning of ultimate solid morphology, entirely avoiding drying phenomena, 13 and guest's expelling, while directing intimate liquid microstructure of emulsion and, intermolecular associations happening at the nanoscale where quantum effects dominate. 14 Although solvent's polarity has been convenient to drive the selective guest's storage over meso-and microporosity, 15 but also in outward surface via anti-solvent induced adsorption, 16 straight-forward carrier's synthesis around metallic particles keeps being the most discriminatory way to isolate lled mesopores. 17 To the best of our knowledge, use of diffusion techniques harmonizing polar host, organic media, non-polar guest, corresponding interactions and, nal solid morphology, is original to join phases with extreme repellence and additionally, compatible with the employ of templates whose original structure could be damaged under harder conditions (acidity, sonication, vortexing or, high temperature).…”

Section: Introductionmentioning

confidence: 99%

Joining host/guest with contrary affinity at the nanoscale by chemical bonds or non-covalent interactions with organic media under diffusion: control of embedded versus exposed magnetite dispersions.

Jansat¹,

Moncusi

2021

Preprint

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Emulating natural dynamism distributing earth minerals using diffusion and gravity, herein it is reported a strategy to unite nanostructured materials of similar size but intrinsic physical repellence, magnetite guest bestowed with C18 alkyl chain ligands and highly hydrophilic ammonium dawsonite NH4Al(OH)2CO3 host, based in electromagnetic and chemical forces. Notwithstanding augmented polarity of nanostructured surface’s carrier, has been used as fine-tuning tool in conjunction with continuum, for triggering a disseminated array of specific interactions covering entire carrier NH4+-RDW-NP periphery. Strong interactions heighten enthalpic contributions balancing unfavourable entropic penalty. Shelter adsorbs diffused guest like conventional Fe3O4-NP dispersions but additionally, whether restricts void’s access or, sinters carrier enabling isolation of a second morphology where magnetite is quantitatively embedded into cavities left between agglomerates. Reported deposition protocol extends sort of practical interactions beyond the known dipole-dipole derived ones, to ion-p and truly chemical coordination bonds, strengthening wetting interfaces that define noticeable g-Al2O3 crystalline domains at minor temperatures. Manuscript illustrates how certain organic media may assist to reliable guest depositions in, hydrotalcite to alumina carriers within controlled morphology, at the same weight level than common procedures reported for more akin host/guest. Interestingly, protocol enables practical SBET measurements for solids with significative contributions of interparticle porosity. Detrimental effects are also addressed.

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“…Extensive research revealed cobalt spinel as one of the most active phases for the process of N 2 O decomposition (deN 2 O process) [6][7][8]. The catalytic performance of Co 3 O 4 can be significantly enhanced by tuning the composition and crystal morphology (controlled faceting) [9][10][11]. Optimization of the chemical composition of the cobalt spinel via controlled addition of dopants can result in a spectacular improvement of catalytic performance.…”

Section: Introductionmentioning

confidence: 99%

Bulk, Surface and Interface Promotion of Co3O4 for the Low-Temperature N2O Decomposition Catalysis

et al. 2019

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Nanocrystalline cobalt spinel has been recognized as a very active catalytic material for N2O decomposition. Its catalytic performance can be substantially modified by proper doping with alien cations with precise control of their loading and location (spinel surface, bulk, and spinel-dopant interface). Various doping scenarios for a rational design of the optimal catalyst for low-temperature N2O decomposition are analyzed in detail and the key reactivity descriptors are identified (content and topological localization of dopants, their redox vs. non-redox nature and catalyst work function). The obtained results are discussed in the broader context of the available literature data to establish general guidelines for the rational design of the N2O decomposition catalyst based on a cobalt spinel platform.

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Influence of preparation method on dispersion of cobalt spinel over alumina extrudates and the catalyst deN 2 O activity

Cited by 33 publications

References 37 publications

Synthesis and Mathematical Modelling of the Preparation Process of Nickel-Alumina Catalysts with Egg-Shell Structures for Syngas Production via Reforming of Clean Model Biogas

Synthesis and Mathematical Modelling of the Preparation Process of Nickel-Alumina Catalysts with Egg-Shell Structures for Syngas Production via Reforming of Clean Model Biogas

Joining host/guest with contrary affinity at the nanoscale by chemical bonds or non-covalent interactions with organic media under diffusion: control of embedded versus exposed magnetite dispersions.

Bulk, Surface and Interface Promotion of Co3O4 for the Low-Temperature N2O Decomposition Catalysis

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