Hierarchical SAPO-11 molecular sieve-based catalysts for enhancing the double-branched hydroisomerization of alkanes

Wen, Chenglong; Wang, Xueman; Xu, Jundong; Fan, Yu

doi:10.1016/j.fuel.2019.115821

Cited by 46 publications

(17 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At low relative pressure (10 –5 ≤ P/P 0 ≤ 10 –2 ), the amount of N 2 adsorption in all samples rose dramatically, which was attributable to N 2 filling the micropores ( Du et al, 2019 ). Within the relative pressure P/P 0 range of 0.4–0.9, all samples showed clear hysteresis loops, showing that these samples have a lot of mesopores ( Wen et al, 2019 ). The hysteresis loop of NiSAPO-11 is clearly larger than that of other samples, indicating that NiSAPO-11 has a more mesoporous structure than other samples.…”

Section: Resultsmentioning

confidence: 98%

Hydroisomerization of n-Hexadecane Over Nickel-Modified SAPO-11 Molecular Sieve-Supported NiWS Catalysts: Effects of Modification Methods

et al. 2022

View full text Add to dashboard Cite

The complexation-excessive impregnation modification method, which was original in this study, and the ion-exchange method and the in situ modification method were used to synthesize Ni-modified SAPO-11 molecular sieves. With the Ni-modified SAPO-11 samples as support, the corresponding NiWS-supported catalysts for the hydroisomerization of n-hexadecane were prepared. The effects of Ni-modification on SAPO-11 characteristics and the active phase were studied. The structure, morphology, and acidity of SAPO-11, as well as the interaction between active metals and support, the morphology, dispersibility, and stacking number of the active phase, were all changed by Ni-modification methods. The complexation-excessive impregnation modification method deleted a portion of Al from SAPO-11 molecular sieves while simultaneously integrating Ni into the skeletal structure of the surface layer of SAPO-11 molecular sieves, considerably enhancing the acidity of SAPO-11 molecular sieves. Furthermore, during dealumination, ethylenediaminetetraacetic acid generated more mesoporous structures and increased the mesoporous volume of SAPO-11 molecular sieves. Because the complexation-excessive impregnation modification method increased the amount of Ni in the surface framework of the SAPO-11 molecular sieve, it has weakened the interaction between the active phase and the support, improved the properties of the active phase, and greatly improved the hydroisomerization performance of NiW/NiSAPO-11. The yield of i-hexadecane of NiW/NiSAPO-11 increased by 39.3% when compared to NiW/NiSAPO-11. It presented a realistic approach for increasing the acidity of SAPO-11, reducing the interaction between active metals and support, and improving the active phase stacking problem.

show abstract

Section: Resultsmentioning

confidence: 98%

Hydroisomerization of n-Hexadecane Over Nickel-Modified SAPO-11 Molecular Sieve-Supported NiWS Catalysts: Effects of Modification Methods

et al. 2022

View full text Add to dashboard Cite

show abstract

“…The products collected were analyzed on a Shimadzu GC-2014 gas chromatograph equipped with a capillary HP-PONA column, and the qualitative analysis of the products was realized by GC-MS. The conversion of n-C 16 of each catalyst at 340°C was converted into the TOF (turnover frequency, which is used to evaluate the catalytic activity of the catalyst) of each active site, which was calculated by the following equation based on the number of all available active sites ( Wen et al, 2019 ):

where V feed is the feed flow rate of the reactant n-C 16 in mol/h, x is the conversion of n-C 16 at 340°C, n w is the amount of W atoms of the catalyst in mol, and f W is the dispersion degree of W species.…”

Section: Methodsmentioning

confidence: 99%

Synthesis of Nickel In Situ Modified SAPO-11 Molecular Sieves and Hydroisomerization Performance of Their NiWS Supported Catalysts

et al. 2021

View full text Add to dashboard Cite

SAPO-11 molecular sieves were modified with different Ni contents by the in situ modification method. The Ni-modified SAPO-11 molecular sieves were used as the supports to prepare the corresponding NiW-supported catalysts for the hydroisomerization of n-hexadecane. The Ni-modified SAPO-11 and the corresponding NiW-supported catalysts were characterized by X-ray diffraction, scanning electron microscopy, N2 adsorption–desorption, NH3-temperature-programmed desorption, pyridine adsorbed infrared, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The results showed that Ni in situ modification preserved the crystal structure of SAPO-11; increased the BET specific surface area, mesopore volume, and medium and strong Brønsted acid amount of SAPO-11; and increased the stacking number of the active phase of the catalysts. 3Ni-SAPO-11 possessed the largest BET specific surface area, mesopore volume, and medium and strong Brønsted acid amount. NiW/3Ni-SAPO-11 possessed the highest dispersion of the active phase and the highest sulfidation degree of the active metals. The results of the hydroisomerization of n-hexadecane showed that Ni in situ modification improved the catalytic activity and selectivity of the catalysts for the hydroisomerization of n-hexadecane to varying degrees. Especially, NiW/3Ni-SAPO-11 had the highest catalytic activity and isomer selectivity, and the maximum yield of isomeric hexadecane could reach 71.18%.

show abstract

“…Conventional SAPO-11 was synthesized in accordance with a procedure described in the literature (Wen et al 2017(Wen et al , 2019. The obtained gel was composed of 0.4 TEOS: 0.95 P 2 O 5 : 1.2 DPA: 1.0 Al 2 O 3 : 40 H 2 O, and it was placed into a 100 mL reactor and then treated at 473 K for 24 h. The final product was produced by water washing, drying and calcining at 873 K for 6 h, and it was named S-C.…”

Section: Synthesis Of Conventional Sapo-11mentioning

confidence: 99%

n-Nonane hydroisomerization over hierarchical SAPO-11-based catalysts with sodium dodecylbenzene sulfonate as a dispersant

Wen

Wang

et al. 2021

Pet. Sci.

Self Cite

View full text Add to dashboard Cite

To enhance the gasoline octane number, low-octane linear n-alkanes should be converted into their high-octane di-branched isomers via n-alkane hydroisomerization. Therefore, hierarchical SAPO-11-based catalysts are prepared by adding different contents of sodium dodecylbenzene sulfonate (SDBS), and they are applied in n-nonane hydroisomerization. When n(SDBS)/n(SiO2) is less than or equal to 0.125, the synthesized hierarchical molecular sieves are all pure SAPO-11, and as the SDBS content increases, the submicron particle size decreases, and the external surface area (ESA) increases. Additionally, these hierarchical SAPO-11 have smaller submicron particles and higher ESA values than conventional SAPO-11. When n(SDBS)/n(SiO2) is greater than 0.125, with increasing SDBS content (n(SDBS)/n(SiO2) = 0.25), the synthesized SAPO-11 contains amorphous materials, which leads to a decline in the ESA; with the further increase in SDBS content (n(SDBS)/n(SiO2) = 0.5), the products are all amorphous materials. These results indicate that in the case of n(SDBS)/n(SiO2) = 0.125, the synthesized SAPO-11 molecular sieve (S–S3) has the most external Brønsted acid centers and the highest ESA of these SAPO-11, and these advantages favor generation of the di-branched isomers in hydrocarbon hydroisomerization. Among these Pt/SAPO-11 catalysts, Pt/S–S3 displays the highest selectivity to entire isomers (83.4%), the highest selectivity to di-branched isomers (28.1%) and the minimum hydrocracking selectivity (15.7%) in n-nonane hydroisomerization.

show abstract

Hierarchical SAPO-11 molecular sieve-based catalysts for enhancing the double-branched hydroisomerization of alkanes

Cited by 46 publications

References 58 publications

Hydroisomerization of n-Hexadecane Over Nickel-Modified SAPO-11 Molecular Sieve-Supported NiWS Catalysts: Effects of Modification Methods

Hydroisomerization of n-Hexadecane Over Nickel-Modified SAPO-11 Molecular Sieve-Supported NiWS Catalysts: Effects of Modification Methods

Synthesis of Nickel In Situ Modified SAPO-11 Molecular Sieves and Hydroisomerization Performance of Their NiWS Supported Catalysts

n-Nonane hydroisomerization over hierarchical SAPO-11-based catalysts with sodium dodecylbenzene sulfonate as a dispersant

Contact Info

Product

Resources

About