Controlling Isomerization Selectivity in Chiral, Photochromic N,C-Chelate Organoboron Systems with Extended π-Conjugation

2018 ◽  
Vol 83 (19) ◽  
pp. 11970-11977 ◽  
Author(s):  
Soren K. Mellerup ◽  
Cally Li ◽  
Xiang Wang ◽  
Suning Wang
Keyword(s):  
Isomerization Selectivity

scholarly journals Co-loading of Pt and Fe on *BEA Zeolite for Enhanced Isomerization Selectivity in n-Heptane Conversion

2018 ◽  
Vol 47 (11) ◽  
pp. 1428-1430
Author(s):  
Ryosuke Ushiki ◽  
Yoshinori Akada ◽  
Masahiko Matsukata
Keyword(s):  
Bea Zeolite ◽  
Isomerization Selectivity ◽  
Heptane Conversion

scholarly journals Toward Understanding of the Effect of Nucleation Temperature on Porous Structure of Micro-Mesoporous Composite Molecular Sieves and Related Crystallization Mechanism

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 777 ◽  
Author(s):  
Chunwei Shi ◽  
Jingjing Liu ◽  
Wenyuan Wu ◽  
Xue Bian ◽  
Ping Chen ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Porous Structure ◽  
Molecular Sieves ◽  
Crystallization Mechanism ◽  
Nucleation Temperature ◽  
X Ray Diffraction ◽  
Mesoporous Composite ◽  
Transmission Electron ◽  
Isomerization Selectivity ◽  
Crystal Particle

Although micro-mesoporous composite molecular sieves have received significant attention due to their desirable properties, they still lack systematic studies on their crystallization process to achieve controllable synthesis of composite molecular sieves. In this study, a series of Y/SBA-15 micro-mesoporous composite molecular sieves with different porous structures were synthesized by tuning nucleation temperature, based on epitaxial growth on the outer surface of the Y-type crystal particle. All composite molecular sieves were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). Moreover, the effect of nucleation temperature on the structure of composite molecular sieves was investigated, while the crystallization mechanism was also explored. Furthermore, the performance of the molecular sieves on isomerization of n-pentane was investigated, the results suggested that the isomerization selectivity was positively correlated with regularity degree of the mesoporous porous structure, where the highest isomerization reached 95.81%. This work suggests that nucleation temperature plays a key role in structures of micro-mesoporous composite molecular sieves, providing a solid basis for the further development of functional composite molecular sieves.

Single isomerization selectivity of glucose in methanol over Sn-BEC zeolite of homogenous Sn distribution

2017 ◽  
Vol 247 ◽  
pp. 158-165 ◽  
Author(s):  
Guanqun Zhang ◽  
Pei Feng ◽  
Weiping Zhang ◽  
Hao Liu ◽  
Congxin Wang ◽  
...  
Keyword(s):  
Isomerization Selectivity

scholarly journals Zinc-modified Pt/SAPO-11 for improving the isomerization selectivity to dibranched alkanes

2017 ◽  
Vol 38 (3) ◽  
pp. 509-517 ◽  
Author(s):  
Zhichao Yang ◽  
Yunqi Liu ◽  
Jinchong Zhao ◽  
Jianxia Gou ◽  
Kaian Sun ◽  
...  
Keyword(s):  
Isomerization Selectivity

scholarly journals n-Heptane isomerization activities of Pt catalyst supported on micro/mesoporous composites

BMC Chemistry ◽  
2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Z. Ghaderi ◽  
M. H. Peyrovi ◽  
N. Parsafard
Keyword(s):  
Nitrogen Adsorption ◽  
Pt Catalyst ◽  
Isomerization Reaction ◽  
X Ray Diffraction ◽  
Hy Zeolite ◽  
Composite Catalysts ◽  
Isomerization Selectivity ◽  
Catalytic Stability ◽  
Adsorption Desorption ◽  
Heptane Conversion

AbstractPt loaded on a series of MCM-48 silica and composites with HZSM-5 zeolite, HY zeolite, or TiO2 has been prepared and studied for n-heptane isomerization reaction at 200–350 °C. The structural characterization, acid distribution, and morphology of these catalysts were characterized by X-ray diffraction, Fourier transform infrared, UV–Vis diffuse reflectance, scanning electron microscope, temperature-programmed desorption of NH3, and nitrogen adsorption–desorption methods. The results show that these catalysts have a good selectivity to multi branched isomers, while producing low aromatic compounds. Also, these new composite catalysts prove the catalytic stability during the time of reaction. The most desirable results, and significantly higher n-heptane conversion and isomerization selectivity were achieved with Pt/MCM48-HZSM5 catalyst.

scholarly journals Synthesis of Ni-Modified ZSM-5 Zeolites and Their Catalytic Performance in n-Octane Hydroconversion

2020 ◽  
Vol 8 ◽  
Author(s):  
Qiang Wei ◽  
Pengfei Zhang ◽  
Xiaodong Liu ◽  
Wenbin Huang ◽  
Xiayun Fan ◽  
...  
Keyword(s):  
Supported Catalysts ◽  
Synthesis Method ◽  
Textural Properties ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Impregnation Method ◽  
Isomerization Selectivity ◽  
Nimo Catalysts ◽  
Adsorption Desorption

Ni-modified ZSM-5 zeolites with different nickel contents were successfully prepared by the in situ synthesis method and the impregnation method. The synthesized samples were characterized by XRD, SEM, N2 adsorption–desorption isothermals, and Py-FTIR. The characterization results show that both the textural properties and crystallization of Ni-modified ZSM-5 zeolites were preserved well, and their acidic properties can be modulated after nickel modification. The corresponding NiMo catalysts supported on Ni-modified ZSM-5 zeolites were prepared by the incipient wetness co-impregnation method, and their catalytic performances were evaluated in n-octane hydroconversion. Compared to the those modified by the in situ synthesis method, ZSM-5 zeolite-supported catalysts modified by the impregnation method exhibit higher stability and higher isomerization selectivity. This is due to the synergistic effect between Brønsted acid sites and Lewis acid sites on the Ni-modified ZSM-5 zeolites, especially for the NiMo/1Ni-Z5 catalyst.

Sign in / Sign up

Export Citation Format

Share Document