Characterization of alumina—montmorillonite complexes

Sterte, Johan; Otterstedt, Jan-Erik; Thulin, Hans; Massoth, F.E.

doi:10.1016/s0166-9834(00)80991-4

Cited by 21 publications

(17 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Also the carbon is of a much more recalcitrant type needing prolonged heating at high temperature to be removed. This is consistent with alkylation occurring over the alumina when high molecular weight aromatic species can be formed [15,16]. When propyne and butane are passed over the alumina support the conversion of propyne is enhanced, whereas initially the conversion of butane is depressed.…”

Section: Discussionsupporting

confidence: 72%

See 1 more Smart Citation

Transhydrogenation of propyne with butane over a vanadia/θ-alumina catalyst

2015

View full text Add to dashboard Cite

The transhydrogenation of propyne and butane was studied over a 1 % VO x /alumina catalyst at 873 K. In the absence of the vanadia, the alumina support was active for cracking and alkylation. However, the addition of the vanadia reduced the propensity for both cracking and alkylation and added dehydrogenation activity. When propyne and butane were co-fed over the catalyst there was a synergistic effect resulting in an increased conversion of propyne (81 cf. 26 % when fed alone); however, much of this increased conversion was converted to carbon deposited on the catalyst. Transhydrogenation of propyne to propene was detected with an enhanced yield of propene when the propane/butane mix was passed over the catalyst. Taking a yield based on propyne fed then the yield of propene increased from 1.2 to 5.0 %. The conversion of butane to value-added products was also enhanced with all the butane converted accounted for in the production of 1-butene, trans-2-butene, iso-butane and iso-butene.

show abstract

Section: Discussionsupporting

confidence: 72%

“…5.8 % for butane. Such behaviour has been well known for over 60 years [14][15][16] as is the formation of higher molecular weight by-products leading to catalyst coking. Indeed with propyne feed there is a 78 % loss in catalytic activity in 15 min on stream ( Table 1).…”

Section: Discussionmentioning

confidence: 95%

Transhydrogenation of propyne with butane over a vanadia/θ-alumina catalyst

2015

View full text Add to dashboard Cite

show abstract

“…The ion-exchange procedure was as follows: a calculated amount of La(NO 3 ) 3 was dissolved in deionized water, and the HZSM-5 was then mixed with this solution and kept at 343 K with stirring for 10 h. The sample was then filtered, washed with deionized water, and dried in air at 383 K. The sample modified with phosphorus was carried out by impregnation with an aqueous solution of phosphoric acid (pH = 1). The impregnated sample was washed with deionized water, subsequently dried at 393 K, and then calcined at 813 K for 3 h. The La-P/HZSM-5 zeolitic catalyst was prepared by adding the P/HZSM-5 catalyst to a solution of La(NO 3 ) 3 . Hydrothermal treatment of the samples was carried out in a quartz reactor tube.…”

Section: Preparation Of Samplesmentioning

confidence: 99%

“…However, HZSM-5 zeolite is not very stable under severe hydrothermal conditions for a long period of time. Incorporation of multivalent cations, such as rare-earth elements, or modification of the HZSM-5 zeolites by impregnation with H 3 PO 4 [3,[8][9][10], is normally used to enhance the hydrothermal stability of the framework, as well as to preserve the activity and selectivity for cracking [11,12]. It has been found that HZSM-5 zeolites modified with both lanthanum and phosphorus exhibit higher hydrothermal stabilities and excellent selectivities for light alkenes in the RSCC process [2].…”

Section: Introductionmentioning

confidence: 99%

Solid-state MAS NMR studies on the hydrothermal stability of the zeolite catalysts for residual oil selective catalytic cracking

Zhuang

Yang

et al. 2004

Journal of Catalysis

143

124

View full text Add to dashboard Cite

“…La calcinación a una temperatura demasiado elevada provoca la degradación de la microestructura de la arcilla intercalada y, en consecuencia, una pérdida del volumen microporoso. Este comportamiento se ha relacionado con la deshidroxilación de las especies inicialmente intercaladas y con una progresiva degradación tanto del catión intercalado como de la arcilla (35)(36)(37)(38). Ge y col. (1) también han descrito el proceso como el resultado de una redistribución y reestructuración de los polihidroxicationes intercalados, pudiéndose generar una estructura microporosa más uniforme.…”

Section: Introductionunclassified

Factores que controlan las propiedades texturales de arcillas intercaladas con disoluciones de circonio y aluminio

Gil¹,

Vicente²,

Gandı́a³

2000

Bol. Soc. Esp. Ceram. Vidr.

View full text Add to dashboard Cite

En este trabajo se ha estudiado la evolución de las propiedades texturales de una saponita y una montmorillonita intercaladas con disoluciones de circonio y aluminio tras calcinación a 500 ºC. Los sólidos presentaron un diferente comportamiento en función de la naturaleza de la disolución de intercalación y de la arcilla empleada. Tras calcinación, la superficie específica y el volumen microporoso de las arcillas intercaladas con disoluciones de aluminio disminuyeron de manera importante, lo cual se ha relacionado con las distancias interlaminar e interpilar que presentaron los materiales intercalados. Por contra, las superficies específicas de las arcillas intercaladas con disoluciones de circonio aumentaron, probablemente gracias al efecto combinado de la descomposición térmica de los ligandos orgánicos unidos al circonio en los policationes y la posible presencia de partículas mesoporosas de ZrO 2 sobre la superficie de los sólidos. Palabras clave: arcillas intercaladas, distancia interlaminar, distancia interpilar, adsorción de nitrógeno. Factors controlling the textural properties of zirconia and alumina pillared claysThe texture development of a saponite and a montmorillonite, intercalated with zirconium and aluminium oligomers, after calcination at 500 ºC has been studied. Remarkable differences were observed among samples, depending on the source of the intercalating polycations and the parent material. On calcining, the alumina pillared clays suffered noticeable specific surface area and micropore volume losses, which have been related to the interlayer and interpillar distances of the samples. On the contrary, the zirconia pillared clays showed a slight surface area increase, which affected both micropores and mesopores and could be due to the combined effect of the thermal decomposition of the zirconium oligomers and the possible presence of mesoporous ZrO 2 particles.

show abstract

Characterization of alumina—montmorillonite complexes

Cited by 21 publications

References 6 publications

Transhydrogenation of propyne with butane over a vanadia/θ-alumina catalyst

Transhydrogenation of propyne with butane over a vanadia/θ-alumina catalyst

Solid-state MAS NMR studies on the hydrothermal stability of the zeolite catalysts for residual oil selective catalytic cracking

Factores que controlan las propiedades texturales de arcillas intercaladas con disoluciones de circonio y aluminio

Contact Info

Product

Resources

About