Preferential methanation of CO in a syngas involving CO2 at lower temperature range

Choudhury, Muhamad B.I.; Ahmed, Shakeel; Shalabi, Mazen A.; Inui, Tomoyuki

doi:10.1016/j.apcata.2006.08.008

Cited by 90 publications

(44 citation statements)

References 15 publications

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“…On the larger Ru NPs, the selectivity is proposed to be controlled by a site blocking mechanism, where the active Ru surface is essentially covered by strongly adsorbed CO ad , preventing the dissociative adsorption of CO 2 , which corresponds to the previous ideas for the origin of the selectivity in the selective CO methanation over Ru catalysts [17,18]. As the CO concentration and hence the CO ad coverage decreases, CO 2 can adsorb on the resulting empty sites and dissociate to CO ad , which acts as intermediate for the CO 2 methanation [27, 49,50].…”

Section: Kinetic Measurementsmentioning

confidence: 99%

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Influence of the catalyst loading on the activity and the CO selectivity of supported Ru catalysts in the selective methanation of CO in CO2 containing feed gases

Eckle

Augustin

Anfang³

et al. 2012

Catalysis Today

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We have investigated the methanation of CO and CO 2 over Ru/zeolite catalysts with different Ru loading in semi-realistic reformate gases by in situ X-ray absorption spectroscopy (XAS), in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and kinetic measurements. Increasing the Ru loading causes an increase of the mean particle size from 0.9 nm (2.2 wt.% Ru) to 1.9 nm (5.6 wt.% Ru). At the same time, also the activity for CO methanation increases, while the selectivity for CO methanation, which is constant at 100% for reformate gases with 0.6% CO, decreases at low CO contents. The latter findings are interpreted in terms of a change in the physical effects governing the selectivity for CO methanation with increasing Ru particle size, from an inherently low activity for CO 2 dissociation and subsequent CO ad methanation on very small Ru nanoparticles to a site blocking mechanism on larger Ru nanoparticles. In the latter mechanism, CO 2 methanation is hindered by a reaction inhibiting adlayer of CO at higher CO ad coverages, i.e., at not too low CO concentrations, but facile in the absence of a CO adlayer, at lower CO concentrations in the reaction gas mixture.

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Section: Kinetic Measurementsmentioning

confidence: 99%

“…The CO adlayer was proposed to inhibit the (dissociative) adsorption of CO 2 and thus the subsequent methanation reaction [17,18]. In that mechanism, CO 2 methanation will be inhibited as long as the CO partial pressure is sufficiently high to maintain the reaction inhibiting CO adlayer.…”

Section: Introductionmentioning

confidence: 99%

Influence of the catalyst loading on the activity and the CO selectivity of supported Ru catalysts in the selective methanation of CO in CO2 containing feed gases

Eckle

Augustin

Anfang³

et al. 2012

Catalysis Today

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“…Methanation of CO over various carried metal catalysts, such as Co, Ni, Ru, Rh, etc., has been widely investigated from the viewpoint of synthesizing CH 4 from syngas [18][19][20][21][22], and recently also from a viewpoint of residual CO removal for PEM-FC applications [23][24][25][26][27][28][29][30][31].…”

Section: Introductionmentioning

confidence: 99%

CO Methanation Over Ru–Al2O3 Catalysts: Effects of Chloride Doping on Reaction Activity and Selectivity

et al. 2011

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The selective CO methanation (CO-SMET) process via Ru-Al 2 O 3 catalysts was investigated as a tool for complete CO removal in fuel processors, when the H 2 -rich gas so produced is employed for PEM-FCs applications to vehicles, boats, yachts and residential co-generators. CO-SMET seems, in fact, to be a good alternative to the most widely used CO preferential oxidation (CO-PROX) process. The performance of Ru-based catalysts on alumina carrier for efficient CO removal through CO-SMET was studied, exploring the role of two different Ru precursors (chloride and nitrate), and the doping effect of chloride and of Ru load (1%, 3% and 5%). First, two catalytic families (Ru-Al 2 O 3 _Cl and Ru-Al 2 O 3 _NO 3 ) were prepared by incipient wetness impregnation of alumina powder synthesized via solution combustion synthesis, by varying the Ru load. Then, based on the best obtained results, a third catalytic family was prepared adding chloride to Ru-Al 2 O 3 _NO 3 catalysts by impregnation. The CO removal performance was determined at catalyst powder level in a fixed bed micro reactor. Better performances were exhibited when Ru was deposited from chloride precursor, but the post-addition of chlorine to fresh RuAl 2 O 3 catalysts prepared with nitrate precursor tremendously improved their selectivity toward CO methanation. In particular, with both 1% and 3% Ru-Al_NO 3 catalyst chlorine doped, complete CO conversion was reached in a proper temperature range where the CO 2 methanation was suitably kept at a low acceptable level.

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“…This is in agreement with literatures [15][16][17] and attributed to preferential adsorption of CO on the metal surface. As CO concentration decreased to a low value, CO 2 could initially be adsorbed on the spare metal surface and hydrogenated [18][19][20]. Figure 7 shows XRD patterns of the catalysts 20%Ni/ Mg 1− Ni O-400-( = 500 ∘ C∼800 ∘ C) used in the CO-SMET reactions.…”

Section: Effect Of Reduction Temperature a Series Of Catalysts 20%nimentioning

confidence: 99%

Phase Composition of Ni/Mg_1−xNi_xO as a Catalyst Prepared for Selective Methanation of CO in H₂‐Rich Gas

Zhang

Gao

2015

Journal of Nanomaterials

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Supported Ni catalysts Ni/Mg 1− Ni O were prepared by reducing samples NiO-MgO in H 2 /N 2 mixture gas at 500 ∘ C∼800 ∘ C for selective methanation of CO in H 2 -rich gas (CO-SMET). The samples NiO-MgO were obtained by heating water slurry of MgO and Ni(NO 3 ) 2 in a rotary evaporator at 80 ∘ C and a final calcination in air at 400 ∘ C∼800 ∘ C. X-ray diffraction (XRD) and temperature programmed reduction (TPR) measurements demonstrate that the samples NiO-MgO were composed of solid solution Mg 1− Ni O as the main phase and a minor amount of NiO at calcination temperature of 400 ∘ C, and amount of the NiO was decreased as calcination temperature increased. Phase composition of the catalysts Ni/Mg 1− Ni O was estimated by the Rietveld method. Effects of reduction temperature, feed Ni/Mg ratio, and calcination temperature on phase composition and catalytic activity of the catalysts were investigated. It is clear that CO conversion was generally enhanced by an increased amount of metallic Ni of the catalysts.

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Preferential methanation of CO in a syngas involving CO2 at lower temperature range

Cited by 90 publications

References 15 publications

Influence of the catalyst loading on the activity and the CO selectivity of supported Ru catalysts in the selective methanation of CO in CO2 containing feed gases

Influence of the catalyst loading on the activity and the CO selectivity of supported Ru catalysts in the selective methanation of CO in CO2 containing feed gases

CO Methanation Over Ru–Al2O3 Catalysts: Effects of Chloride Doping on Reaction Activity and Selectivity

Phase Composition of Ni/Mg_1−xNi_xO as a Catalyst Prepared for Selective Methanation of CO in H₂‐Rich Gas

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Preferential methanation of CO in a syngas involving CO2 at lower temperature range

Cited by 90 publications

References 15 publications

Influence of the catalyst loading on the activity and the CO selectivity of supported Ru catalysts in the selective methanation of CO in CO2 containing feed gases

Influence of the catalyst loading on the activity and the CO selectivity of supported Ru catalysts in the selective methanation of CO in CO2 containing feed gases

CO Methanation Over Ru–Al2O3 Catalysts: Effects of Chloride Doping on Reaction Activity and Selectivity

Phase Composition of Ni/Mg1−xNixO as a Catalyst Prepared for Selective Methanation of CO in H2‐Rich Gas

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Phase Composition of Ni/Mg_1−xNi_xO as a Catalyst Prepared for Selective Methanation of CO in H₂‐Rich Gas