Hydroisomerization of n-decane in the presence of sulfur

Galperin, L.B.; Bradley, S.A.; Mezza, Thomas M.

doi:10.1016/s0926-860x(01)00668-8

Cited by 23 publications

(14 citation statements)

References 13 publications

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“…However, it is well known that without a metal and H 2 present, an acid catalyst rapidly deactivates under conditions favorable for dehydration and alkylation. Numerous examples in the literature [46][47][48] demonstrate that a close proximity of metal and acid sites in the zeolite can greatly improve catalyst stability as well as selectivity for reactions that require bifunctionality. Therefore, it is desirable to find a catalyst with the right metal/acid balance that can undergo the hydrogenation/ dehydration/alkylation in one pot.…”

Section: Hydroalkylation Of M-cresol Over Pt-and Pd-loaded Zeolite Hymentioning

confidence: 99%

Tuning the acid–metal balance in Pd/ and Pt/zeolite catalysts for the hydroalkylation of m-cresol

Anaya

Zhang

Tan

et al. 2015

Journal of Catalysis

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a b s t r a c tThe liquid-phase hydroalkylation of m-cresol catalyzed by zeolite catalysts doped with noble metals was investigated at 473 K and 5200 kPa of H 2 . Metals (Pt and Pd) were incorporated in HY (Si/Al = 30) and HMor (Si/Al = 10) zeolites by incipient wetness impregnation. The structural properties of the samples were characterized by NMR, XPS, and BET. Hydroalkylation of m-cresol involves a series of steps that start with the ring saturation to 3-methylcyclohexanone (MCONE), which is the primary product and is further hydrogenated to methylcyclohexanol (MCNOL) on the metal function. This, in turn, is dehydrated on the acid sites to 3-methylcyclohexene, which readily alkylates the unreacted m-cresol to form bicyclic compounds that fall in the desirable fuel range. In these bifunctional catalysts, differences in intrinsic hydrogenation activity of metals play an important role in determining the final selectivity to alkylated products. In fact, the ratio of number of acid sites (n A ) to exposed metal sites (n M ) can be tuned to maximize the selectivity toward bicyclic compounds because this selectivity is determined by the fate of the intermediate 3-methylcyclohexene (MCENE). That is, if the C@C hydrogenation on the metal is fast compared to alkylation on the acid site, the selectivity decreases. However, if the hydrogenation is too slow, the overall product yield decreases. Thus, to optimize the hydroalkylation yield, a delicate metal/acid balance is required. Moreover, in the absence of metal, the zeolite would deactivate very quickly. Therefore, having the metal and acid functions together is also important for extending the catalyst life. Finally, it has been observed that 3D-pore zeolites, such as HY, are preferred over 1D-pore zeolites such as HMor, which sharply diminish the formation of alkylation compounds, despite being more acidic than HY.

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Section: Hydroalkylation Of M-cresol Over Pt-and Pd-loaded Zeolite Hymentioning

confidence: 99%

Tuning the acid–metal balance in Pd/ and Pt/zeolite catalysts for the hydroalkylation of m-cresol

Anaya

Zhang

Tan

et al. 2015

Journal of Catalysis

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“…Galperin [17] investigated hydroisomerization of n-decane over 0.1% Pt supported on MAPO-31, SAPO-11, SAPO-34, SAPO-41, SAPO-5 and MFI. The same authors [18] observed hydroisomerization of n-decane in the presence of sulfur and studied the effect of metal-acid balance. Elangovan et al [19] observed n-decane hydroconversion over bifunctional catalysts comprising bimetallic Pt-Pd clusters supported on an AlMCM-41 (nSi/nAl=23) mesoporous molecular sieve, where the catalytic activity of the bimetallic Pt-Pd catalysts is higher than monometallic Pt and Pd catalysts.…”

Section: Introductionmentioning

confidence: 99%

Effect of Ni in palladium β-zeolite on hydroisomerization of n-decane

Karthikeyan

Lingappan

Sivasankar

2008

Korean J. Chem. Eng.

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Bifunctional catalysts containing (0.1-0.5 wt%) Nickel and 0.1 wt% of Pd supported on H-β zeolite were synthesized by incipient wetness impregnation method and characterized by XRD, TEM, XPS, TPD and TPR techniques. The catalytic activity of Ni containing and Ni free Pd/H-β Catalysts was studied, and it was found that Ni up to a threshold value (0.3 wt% on β) produced increased the n-decane conversion and isomerization selectivity. When Ni content exceeds the threshold value, the conversion increases but isomerized products decrease. Moreover, Ni containing Pd/H-β showed increased sustainability and favored the protonated cyclopropane (PCP) intermediate mechanism in n-decane isomerization. The catalyst containing 0.3 wt% Ni 0.1 wt% Pd is adjudged as one performing better than other catalysts studied because of the isomerized mixture from it shows better octane number.

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“…Nevertheless, the catalyst that included 20% binder (alumina) and 80% 1 D,10 R zeolite (MgAPSO 31) and containing platinum pref erably deposited on the binder material showed high activity and selectivity during decane hydroisomeriza tion [83]. The activity and selectivity of the bifunctional cat alysts of hydroisomerization based on 1 D,10 R zeo lites increase with the content of the metal component to a certain threshold value; at a relatively small num ber of metal centers, the total reaction rate is limited by the hydrogenation-dehydrogenation rates.…”

Section: Zeolite Synthesis Gelationmentioning

confidence: 99%

Hydroisomerization of long-chain paraffins: Mechanism and catalysts. Part I

Nikiforov¹,

Фадеев²,

Loginova³

et al. 2015

Catal. Ind.

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A review of the literature on the catalysts of hydroisomerization of long chain paraffins is pre sented. Part I describes the mechanisms of paraffin hydroisomerizations and presents an analysis of data on the catalysts of hydroisomerization based on zeolites of various types. Part II is devoted to catalysts based on structured mesoporous materials, partially reduced molybdenum oxides and oxycarbides, and mixtures of tungsten and zirconium oxides. Industrial catalysts that have found use in isodewaxing of diesel fuels and oils are described.

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Hydroisomerization of n-decane in the presence of sulfur

Cited by 23 publications

References 13 publications

Tuning the acid–metal balance in Pd/ and Pt/zeolite catalysts for the hydroalkylation of m-cresol

Tuning the acid–metal balance in Pd/ and Pt/zeolite catalysts for the hydroalkylation of m-cresol

Effect of Ni in palladium β-zeolite on hydroisomerization of n-decane

Hydroisomerization of long-chain paraffins: Mechanism and catalysts. Part I

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