Activation mechanism and microstructural evolution of a YSZ/Ni-alumina catalyst for dry reforming of methane

Braidy, Nadi; Bastien, Samuel; Blanchard, Jasmin; Fauteux‐Lefebvre, Clémence; Achouri, Inès Esma; Abatzoglou, Nicolas

doi:10.1016/j.cattod.2017.03.006

Cited by 30 publications

(14 citation statements)

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“…In our case, it seems that the catalyst was in a state of equilibrium which was a function of operating conditions. This was a very important result and showed that the reaction mechanism was similar to the one explained by Braidy et al [43]. Nevertheless, further investigations are needed to confirm our highly-plausible speculation.…”

supporting

confidence: 58%

“…Then, as the reaction continued over time, the amount of H2O increased inside the reactor which first re-oxidized a part of Ni 0 into Ni 2+ [41] and favored sintering of Ni particles [42]. We consider that this mechanism, which was explained in detail by Braidy et al [43] for methane SR over Ni/Al2O3-YSZ spinel catalyst, also prevails in the case of the Ni-UGSO catalyst. The low selectivity of CO and H 2 after bio-oil WU SR were due to high O and H 2 O content (%O = 73%, %H 2 O = 52.3%, O/C ≈ 3).…”

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confidence: 94%

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Bio-Oil Steam Reforming over a Mining Residue Functionalized with Ni as Catalyst: Ni-UGSO

et al. 2017

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Bio-oil reforming is considered for syngas or H 2 production. In this work, we studied the steam reforming (SR) of two raw bio-oils without adding external steam, using a recently-developed catalyst, Ni-UGSO. Experiments were performed at temperature (T) = 750-850 • C and weight hourly space velocity (WHSV) = 1.7-7.1 g/g cat /h to assess C conversion (X C ) and product yields. The results show that, in all conditions and with both bio-oils tested, the catalyst is stable for the entire duration of the tests (~500 min) even when some C deposition occurred and that only at the highest WHSV tested there is a slight deactivation. In all tests, catalytic activity remained constant after a first, short, transient state, which corresponded to catalyst activation. The highest yields and conversions, with Y H 2 , Y CO and X C of 94%, 84% and 100%, respectively, were observed at temperatures above 800 • C and WHSV = 1.7 g/g cat /h. The amount of H 2 O in the bio-oils had a non-negligible effect on catalyst activity, impacting Y H 2 , Y CO and X C values. It was observed that, above a critical amount of H 2 O, the catalyst was not fully activated. However, higher H 2 O content led to the reduction of C deposits as well as lower Y H 2 and Y CO and, through the water-gas-shift reaction, to higher Y CO 2 (CO 2 selectivity). Fresh and spent catalysts were analyzed by physisorption (BET), X-ray diffraction, scanning electron microscopy and thermogravimetric analysis: the results reveal that, during the oils' SR reaction, the initial spinel (Ni-Fe-Mg-Al) structures decreased over time-on-stream (TOS), while metallic Ni, Fe and their alloy phases appeared. Although significant sintering was observed in used catalysts, especially at high H 2 O/C ratio, the catalyst's specific surface generally increased; the latter was attributed to the presence of nanometric metallic Ni and Ni-Fe alloy particles formed by reduction reactions. A small amount of C (4%) was formed at low H 2 O/C.

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confidence: 58%

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confidence: 94%

Bio-Oil Steam Reforming over a Mining Residue Functionalized with Ni as Catalyst: Ni-UGSO

et al. 2017

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“…The interaction between Ni and Al 2 O 3 supports can lead to the formation of NiAl 2 O 4 spinel structure, which can provide stable and highly dispersed metallic Ni particles via reduction [65]. The microstructural evolution of Ni-alumina catalyst at elevated temperature under reducing atmosphere has been investigated by in-situ XRD and TEM analysis [65].…”

Section: Enhancement Of Dispersion and Thermal Stability Of Ni Nanopamentioning

confidence: 99%

“…The microstructural evolution of Ni-alumina catalyst at elevated temperature under reducing atmosphere has been investigated by in-situ XRD and TEM analysis [65]. Braidy [67].…”

Section: Enhancement Of Dispersion and Thermal Stability Of Ni Nanopamentioning

confidence: 99%

Recent Scientific Progress on Developing Supported Ni Catalysts for Dry (CO2) Reforming of Methane

Seo

2018

Catalysts

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Two major green house gases (CO 2 and CH 4 ) can be converted into useful synthetic gas (H 2 and CO) during dry reforming of methane (DRM) reaction, and a lot of scientific efforts has been made to develop efficient catalysts for dry reforming of methane (DRM). Noble metal-based catalysts can effectively assist DRM reaction, however they are not economically viable. Alternatively, non-noble based catalysts have been studied so far, and supported Ni catalysts have been considered as a promising candidate for DRM catalyst. Main drawback of Ni catalysts is its catalytic instability under operating conditions of DRM (>700 • C). Recently, it has been demonstrated that the appropriate choice of metal-oxide supports can address this issue since the chemical and physical of metal-oxide supports can prevent coke formation and stabilize the small Ni nanoparticles under harsh conditions of DRM operation. This mini-review covers the recent scientific findings on the development of supported Ni catalysts for DRM reaction, including the synthetic methods of supported Ni nanoparticles with high sintering resistance.

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“…Therefore, considerable effort has been devoted to exploring and optimizing their properties. [33][34][35][36] Perhaps most important is the fact that it is relatively difficult to obtain high surface area spinel-based active catalysts due to the fact that high temperature processing is required simply to produce the spinel structure. Such high temperature processing frequently equates to extensive loss of surface area.…”

Section: Introductionmentioning

confidence: 99%

Chemical modification in and on single phase [NiO]_0.5[Al₂O₃]_0.5 nanopowders produces “chocolate chip‐like” Ni_x@[NiO]_0.5‐x[Al₂O₃]_0.5 nanocomposite nanopowders

Wang

Sun

et al. 2019

J Am Ceram Soc

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Phase‐pure [NiO]0.5[Al2O3]0.5 spinel nanoparticles (NPs) with limited aggregation were obtained via liquid‐feed flame spray pyrolysis (LF‐FSP) by combusting metalloorganic precursor solutions. Thereafter “chocolate chip‐like” Nix[NiO0.5‐x][Al2O3]0.5 nanoparticles consisting of primary [NiO0.5‐x][Al2O3]0.5 particles with average particle sizes of 40‐60 nm decorated with Ni metal particles (<10 nm in diameter) dispersed on the surface were synthesized by heat treating the spinel NPs at 800°C/7 h in flowing 5% H2:N2 100 mL/min in a fluidized bed reactor. The synthesized materials were characterized using TEM, XRD, FTIR, and TGA/DTA. The Ni depleted areas consist primarily of γ‐Al2O3. The Ni content (800°C) was determined by TGA to be ≈11.3 wt.% based on TGA oxidation behavior. The successful synthesis of such nanocomposites with limited aggregation on a high temperature support provides a facile route to synthesize well‐defined NP catalysts. This work serves as a baseline study for an accompanying paper, wherein thin, flexible, dense films made from these same NPs are used as regenerable catalysts for carbon nanotube syntheses.

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Activation mechanism and microstructural evolution of a YSZ/Ni-alumina catalyst for dry reforming of methane

Cited by 30 publications

References 23 publications

Bio-Oil Steam Reforming over a Mining Residue Functionalized with Ni as Catalyst: Ni-UGSO

Bio-Oil Steam Reforming over a Mining Residue Functionalized with Ni as Catalyst: Ni-UGSO

Recent Scientific Progress on Developing Supported Ni Catalysts for Dry (CO2) Reforming of Methane

Chemical modification in and on single phase [NiO]_0.5[Al₂O₃]_0.5 nanopowders produces “chocolate chip‐like” Ni_x@[NiO]_0.5‐x[Al₂O₃]_0.5 nanocomposite nanopowders

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Activation mechanism and microstructural evolution of a YSZ/Ni-alumina catalyst for dry reforming of methane

Cited by 30 publications

References 23 publications

Bio-Oil Steam Reforming over a Mining Residue Functionalized with Ni as Catalyst: Ni-UGSO

Bio-Oil Steam Reforming over a Mining Residue Functionalized with Ni as Catalyst: Ni-UGSO

Recent Scientific Progress on Developing Supported Ni Catalysts for Dry (CO2) Reforming of Methane

Chemical modification in and on single phase [NiO]0.5[Al2O3]0.5 nanopowders produces “chocolate chip‐like” Nix@[NiO]0.5‐x[Al2O3]0.5 nanocomposite nanopowders

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Chemical modification in and on single phase [NiO]_0.5[Al₂O₃]_0.5 nanopowders produces “chocolate chip‐like” Ni_x@[NiO]_0.5‐x[Al₂O₃]_0.5 nanocomposite nanopowders