Catalytic Activity of Pt Loaded Zeolites for Hydroisomerization of n-Hexane Using Supercritical CO2

Usama A. Al-Rawi; Farooq Sher; Abu Hazafa; Tahir Rasheed; Nawar K. Al-Shara; Eder C. Lima; Jabir Shanshool

doi:10.1021/acs.iecr.0c05184

Catalytic Activity of Pt Loaded Zeolites for Hydroisomerization of n-Hexane Using Supercritical CO₂

Usama A. Al-Rawi, Farooq Sher, Abu Hazafa, Tahir Rasheed, Nawar K. Al-Shara, Eder C. Lima, Jabir Shanshool

Research output: Contribution to journal › Article › peer-review

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Abstract

The present study investigates the synthesis of novel strontium (Sr) and barium (Ba) modified crystalline zeolites including Zeolite Socony Mobil-5 (ZSM-5) and Mordenite (MOR) utilizing a batchwise ion-exchange method with an appropriate chloride solution of 3 N at pH 7.2 and 50 °C. Modified zeolites (Ba-ZSM-5 and Ba-MOR, Sr-ZSM-5 and Sr-MOR) were coated with an inert metal (Pt) by a novel supercritical CO2 method using PtMe2COD as a precursor for n-hexane hydroisomerization in a microreactor unit at different temperatures (250–325 °C), H2/HC ratios of 3, 6, and 9, and a pressure of 5 bar. The acidic and physical features of Pt loaded zeolites were systematically characterized using FT-IR, XRD, BET surface area measurements, TGA, and TEM techniques. It is found that the metal loading in scCO2 results in more uniform and very small metal nanoparticle (1.37 nm) dispersion with high stability after reduction. It is also revealed that high loading pressure in scCO2 (280–300 bar) results in higher catalytic activity and surface area. The maximum conversion and selectivity of about 80 and 90% were achieved for n-hexane isomerization at 275 °C and a H2/HC ratio of 6 for Pt/Sr-ZSM-5 catalyst. Results reported that Pt loaded over all zeolites (H-MOR, Sr-MOR, Ba-MOR, H-ZSM-5, Ba-ZSM-5, and Sr-ZSM-5) by the scCO2 method showed the minimum production of cracking products (C1–C5) and maximum isomeric products including iso-C6 isomers (2,2-DMB, 2,3-DMB, 2-MP, and 3-MP). Furthermore, the overall results of the rate of reaction revealed that Pt/Sr-ZSM-5 and Pt/Ba-ZSM-5 catalysts showed a better rate of isomerization (46.44%) and conversion (47%) for n-hexane at 300 °C and a H2/HC ratio of 9 with a minimum rate of cracking. However, it is concluded that the small, pored size Pt loaded ZSM-5 zeolite showed the highest catalytical activity compared to large pored MOR zeolite making it of great interest for diesel and gasoline formation in the oil refining industry.

Original language	English
Pages (from-to)	22092-22106
Number of pages	15
Journal	Industrial & Engineering Chemistry Research
Volume	59
Issue number	51
Early online date	10 Dec 2020
DOIs	https://doi.org/10.1021/acs.iecr.0c05184
Publication status	Published - 23 Dec 2020

Funder

Funding Information: The authors are grateful for the financial support from the Foundation for Research Support of the State of Rio Grande do Sul – FAPERGS [19/2551-0001865-7] and National Council for Scientific and Technological Development – CNPq [303.622/2017-2]. The authors are also thankful for the financial support from the Ministry of Higher Education and Scientific Research of Iraq. Publisher Copyright: © 2020 American Chemical Society

Keywords

Industrial and Manufacturing Engineering
General Chemical Engineering
General Chemistry

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10.1021/acs.iecr.0c05184

Cite this

@article{dab9051ebfe04529a0b730f775f5ba26,

title = "Catalytic Activity of Pt Loaded Zeolites for Hydroisomerization of n-Hexane Using Supercritical CO2",

abstract = "The present study investigates the synthesis of novel strontium (Sr) and barium (Ba) modified crystalline zeolites including Zeolite Socony Mobil-5 (ZSM-5) and Mordenite (MOR) utilizing a batchwise ion-exchange method with an appropriate chloride solution of 3 N at pH 7.2 and 50 °C. Modified zeolites (Ba-ZSM-5 and Ba-MOR, Sr-ZSM-5 and Sr-MOR) were coated with an inert metal (Pt) by a novel supercritical CO2 method using PtMe2COD as a precursor for n-hexane hydroisomerization in a microreactor unit at different temperatures (250–325 °C), H2/HC ratios of 3, 6, and 9, and a pressure of 5 bar. The acidic and physical features of Pt loaded zeolites were systematically characterized using FT-IR, XRD, BET surface area measurements, TGA, and TEM techniques. It is found that the metal loading in scCO2 results in more uniform and very small metal nanoparticle (1.37 nm) dispersion with high stability after reduction. It is also revealed that high loading pressure in scCO2 (280–300 bar) results in higher catalytic activity and surface area. The maximum conversion and selectivity of about 80 and 90% were achieved for n-hexane isomerization at 275 °C and a H2/HC ratio of 6 for Pt/Sr-ZSM-5 catalyst. Results reported that Pt loaded over all zeolites (H-MOR, Sr-MOR, Ba-MOR, H-ZSM-5, Ba-ZSM-5, and Sr-ZSM-5) by the scCO2 method showed the minimum production of cracking products (C1–C5) and maximum isomeric products including iso-C6 isomers (2,2-DMB, 2,3-DMB, 2-MP, and 3-MP). Furthermore, the overall results of the rate of reaction revealed that Pt/Sr-ZSM-5 and Pt/Ba-ZSM-5 catalysts showed a better rate of isomerization (46.44%) and conversion (47%) for n-hexane at 300 °C and a H2/HC ratio of 9 with a minimum rate of cracking. However, it is concluded that the small, pored size Pt loaded ZSM-5 zeolite showed the highest catalytical activity compared to large pored MOR zeolite making it of great interest for diesel and gasoline formation in the oil refining industry.",

keywords = "Industrial and Manufacturing Engineering, General Chemical Engineering, General Chemistry",

author = "Al-Rawi, {Usama A.} and Farooq Sher and Abu Hazafa and Tahir Rasheed and Al-Shara, {Nawar K.} and Lima, {Eder C.} and Jabir Shanshool",

year = "2020",

month = dec,

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doi = "10.1021/acs.iecr.0c05184",

language = "English",

volume = "59",

pages = "22092--22106",

journal = "Industrial & Engineering Chemistry Research",

issn = "0888-5885",

publisher = "American Chemical Society (ACS)",

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TY - JOUR

T1 - Catalytic Activity of Pt Loaded Zeolites for Hydroisomerization of n-Hexane Using Supercritical CO2

AU - Al-Rawi, Usama A.

AU - Sher, Farooq

AU - Hazafa, Abu

AU - Rasheed, Tahir

AU - Al-Shara, Nawar K.

AU - Lima, Eder C.

AU - Shanshool, Jabir

PY - 2020/12/23

Y1 - 2020/12/23

N2 - The present study investigates the synthesis of novel strontium (Sr) and barium (Ba) modified crystalline zeolites including Zeolite Socony Mobil-5 (ZSM-5) and Mordenite (MOR) utilizing a batchwise ion-exchange method with an appropriate chloride solution of 3 N at pH 7.2 and 50 °C. Modified zeolites (Ba-ZSM-5 and Ba-MOR, Sr-ZSM-5 and Sr-MOR) were coated with an inert metal (Pt) by a novel supercritical CO2 method using PtMe2COD as a precursor for n-hexane hydroisomerization in a microreactor unit at different temperatures (250–325 °C), H2/HC ratios of 3, 6, and 9, and a pressure of 5 bar. The acidic and physical features of Pt loaded zeolites were systematically characterized using FT-IR, XRD, BET surface area measurements, TGA, and TEM techniques. It is found that the metal loading in scCO2 results in more uniform and very small metal nanoparticle (1.37 nm) dispersion with high stability after reduction. It is also revealed that high loading pressure in scCO2 (280–300 bar) results in higher catalytic activity and surface area. The maximum conversion and selectivity of about 80 and 90% were achieved for n-hexane isomerization at 275 °C and a H2/HC ratio of 6 for Pt/Sr-ZSM-5 catalyst. Results reported that Pt loaded over all zeolites (H-MOR, Sr-MOR, Ba-MOR, H-ZSM-5, Ba-ZSM-5, and Sr-ZSM-5) by the scCO2 method showed the minimum production of cracking products (C1–C5) and maximum isomeric products including iso-C6 isomers (2,2-DMB, 2,3-DMB, 2-MP, and 3-MP). Furthermore, the overall results of the rate of reaction revealed that Pt/Sr-ZSM-5 and Pt/Ba-ZSM-5 catalysts showed a better rate of isomerization (46.44%) and conversion (47%) for n-hexane at 300 °C and a H2/HC ratio of 9 with a minimum rate of cracking. However, it is concluded that the small, pored size Pt loaded ZSM-5 zeolite showed the highest catalytical activity compared to large pored MOR zeolite making it of great interest for diesel and gasoline formation in the oil refining industry.

AB - The present study investigates the synthesis of novel strontium (Sr) and barium (Ba) modified crystalline zeolites including Zeolite Socony Mobil-5 (ZSM-5) and Mordenite (MOR) utilizing a batchwise ion-exchange method with an appropriate chloride solution of 3 N at pH 7.2 and 50 °C. Modified zeolites (Ba-ZSM-5 and Ba-MOR, Sr-ZSM-5 and Sr-MOR) were coated with an inert metal (Pt) by a novel supercritical CO2 method using PtMe2COD as a precursor for n-hexane hydroisomerization in a microreactor unit at different temperatures (250–325 °C), H2/HC ratios of 3, 6, and 9, and a pressure of 5 bar. The acidic and physical features of Pt loaded zeolites were systematically characterized using FT-IR, XRD, BET surface area measurements, TGA, and TEM techniques. It is found that the metal loading in scCO2 results in more uniform and very small metal nanoparticle (1.37 nm) dispersion with high stability after reduction. It is also revealed that high loading pressure in scCO2 (280–300 bar) results in higher catalytic activity and surface area. The maximum conversion and selectivity of about 80 and 90% were achieved for n-hexane isomerization at 275 °C and a H2/HC ratio of 6 for Pt/Sr-ZSM-5 catalyst. Results reported that Pt loaded over all zeolites (H-MOR, Sr-MOR, Ba-MOR, H-ZSM-5, Ba-ZSM-5, and Sr-ZSM-5) by the scCO2 method showed the minimum production of cracking products (C1–C5) and maximum isomeric products including iso-C6 isomers (2,2-DMB, 2,3-DMB, 2-MP, and 3-MP). Furthermore, the overall results of the rate of reaction revealed that Pt/Sr-ZSM-5 and Pt/Ba-ZSM-5 catalysts showed a better rate of isomerization (46.44%) and conversion (47%) for n-hexane at 300 °C and a H2/HC ratio of 9 with a minimum rate of cracking. However, it is concluded that the small, pored size Pt loaded ZSM-5 zeolite showed the highest catalytical activity compared to large pored MOR zeolite making it of great interest for diesel and gasoline formation in the oil refining industry.

KW - Industrial and Manufacturing Engineering

KW - General Chemical Engineering

KW - General Chemistry

UR - http://www.scopus.com/inward/record.url?scp=85098775582&partnerID=8YFLogxK

U2 - 10.1021/acs.iecr.0c05184

DO - 10.1021/acs.iecr.0c05184

M3 - Article

SN - 0888-5885

VL - 59

SP - 22092

EP - 22106

JO - Industrial & Engineering Chemistry Research

JF - Industrial & Engineering Chemistry Research

IS - 51

ER -