Promoter effect of Ag and La on stability of NI/AL2o3 catalysts in reforming of methane processes

Parizotto, N.V.; Fernández, Rosa; Marques, C.M.P.; Bueno, J.M.C.

doi:10.1016/s0167-2991(07)80168-6

Cited by 12 publications

(11 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The catalysts with Ag loading of 0.3 or 0.6 wt% submitted to stability tests showed high resistance to coke deposition reported by Bueno et al [32]. They further found that at more oxidant conditions (autothermal reforming of methane, ATRM and POM) the redox process led to NiO formation and catalyst deactivation by NiAl 2 O 4 formation [33]. At higher temperatures most probably due to Ag evaporation from Ag doped Ni/YSZ surface, severe anode catalytic and electro-catalytic activity degradation was observed by Neophytides et al [34].…”

Section: Catalytic Activity Of Ni-au Catalysts and Comparison With Otmentioning

confidence: 64%

“…Bueno and co-workers have prepared Ni/γ-Al 2 O 3 modified with Ag by co-impregnation method [32,33]. The impregnated samples were dried at 353 K overnight and calcined under flowing air at 723 K for 2 h. Finally, the samples were reduced in H 2 flow, heated at 10 K/min and held at 1073 K for 2 h. Figure 3 shows the in situ Ni K-edge XANES-TPR-H 2 spectra of the oxidized 5 wt% Ni/γ-Al 2 O 3 and that doped by 0.6 wt% Ag at different temperatures.…”

Section: Ni Metal Particles Modified With Agmentioning

confidence: 99%

See 1 more Smart Citation

Ni-Based Catalysts for Low Temperature Methane Steam Reforming: Recent Results on Ni-Au and Comparison with Other Bi-Metallic Systems

et al. 2013

View full text Add to dashboard Cite

Steam reforming of light hydrocarbons provides a promising method for hydrogen production. Ni-based catalysts are so far the best and the most commonly used catalysts for steam reforming because of their acceptably high activity and significantly lower cost in comparison with alternative precious metal-based catalysts. However, nickel catalysts are susceptible to deactivation from the deposition of carbon, even when operating at steam-to-carbon ratios predicted to be thermodynamically outside of the carbon-forming regime. Reactivity and deactivation by carbon formation can be tuned by modifying Ni surfaces with a second metal, such as Au through alloy formation. In the present review, we summarize the very recent progress in the design, synthesis, and characterization of supported bimetallic Ni-based catalysts for steam reforming. The progress in the modification of Ni with noble metals (such as Au and Ag) is discussed in terms of preparation, characterization and pretreatment methods. Moreover, the comparison with the effects of other metals (such as Sn, Cu, Co, Mo, Fe, Gd and B) is addressed. The differences of catalytic activity, thermal stability and carbon species OPEN ACCESSCatalysts 2013, 3 564 between bimetallic and monometallic Ni-based catalysts are also briefly shown.

show abstract

Section: Catalytic Activity Of Ni-au Catalysts and Comparison With Otmentioning

confidence: 64%

Section: Ni Metal Particles Modified With Agmentioning

confidence: 99%

Ni-Based Catalysts for Low Temperature Methane Steam Reforming: Recent Results on Ni-Au and Comparison with Other Bi-Metallic Systems

et al. 2013

View full text Add to dashboard Cite

show abstract

“…The addition of Au and Ag was reported to reduce the coke formation on the nickel catalysts during hydrocarbon reforming reactions, reducing the catalyst deactivation [10][11][12][13]. The addition of cerium oxide and lanthanum oxide to alumina supported noble metal catalysts (Pt and Pd) was reported to improve the catalyst stability for MSR [14,15].…”

Section: Introductionmentioning

confidence: 99%

“…redox equilibria on the catalyst surface enhances the oxidation of deposited carbon reducing the catalysts deactivation through coke deposition. Lanthanum oxide has been studied as promoter of alumina supported Ni catalysts for steam and dry reforming of methane [12,16,20,21] and was proposed to have a stabilizing effect on the Ni particles deposited on alumina.…”

Section: Introductionmentioning

confidence: 99%

Supported nickel catalysts for low temperature methane steam reforming: comparison between metal additives and support modification

Dan

Miheţ

Biriş

et al. 2011

Reac Kinet Mech Cat

View full text Add to dashboard Cite

The effect of Ag (1 wt%) and Au (1 wt%) on the catalytic properties of Ni/Al 2 O 3 (7 wt% Ni) for methane steam reforming (MSR) was studied in parallel with the effect of CeO 2 (6 wt%) and La 2 O 3 (6 wt%) addition. The addition of 1 wt% Ag to the alumina supported nickel catalyst drastically decreased its catalytic properties at temperatures lower than 600°C, due to the blockage of metal catalytic centers by silver deposition. The addition of Au and CeO 2 (La 2 O 3 ) to the nickel catalyst improved the methane conversion, CO 2 selectivity and hydrogen production at low reaction temperatures (t \ 600°C). At 700°C under our working conditions, the additives have no important effect in hydrogen production by MSR. The best hydrogen production at low temperatures was obtained for Ni-Au/Al 2 O 3 , due to the higher CO 2 selectivity, cumulated with slightly higher methane conversion in comparison with Ni/CeO 2 -Al 2 O 3 . At high temperature, Ni/CeO 2 -Al 2 O 3 is stable for 48 h on stream. are mainly deactivated due to the temperature effect on Au and Ag nanoparticles and less through coke formation. On , crystalline, graphitic carbon was deposited after 48 h of reaction leading to catalyst partial deactivation. On the Ni/CeO 2 -Al 2 O 3 surface, a porous amorphous form of deposited carbon was found, which does not decrease its catalytic activity after 48 h of reaction.Electronic supplementary material The online version of this article (

show abstract

“…This means that the development of the catalyst support is usually the subject of investigation in order to enhance both the catalytic activity and the stability of the Ni-based catalysts. The effect of promoter, such as Ag, La [11], Mg, Mn, K, and Ca [12], was investigated for improving the stability of the Ni catalysts for CH 4 …”

Section: Introductionmentioning

confidence: 99%

Activity of different zeolite-supported Ni catalysts for methane reforming with carbon dioxide

Luengnaruemitchai

Kaengsilalai

2008

Chemical Engineering Journal

126

View full text Add to dashboard Cite

Promoter effect of Ag and La on stability of NI/AL2o3 catalysts in reforming of methane processes

Cited by 12 publications

References 8 publications

Ni-Based Catalysts for Low Temperature Methane Steam Reforming: Recent Results on Ni-Au and Comparison with Other Bi-Metallic Systems

Ni-Based Catalysts for Low Temperature Methane Steam Reforming: Recent Results on Ni-Au and Comparison with Other Bi-Metallic Systems

Supported nickel catalysts for low temperature methane steam reforming: comparison between metal additives and support modification

Activity of different zeolite-supported Ni catalysts for methane reforming with carbon dioxide

Contact Info

Product

Resources

About