Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 

Saved Queries

Sign in to use this feature.

Search Filter Reset All

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
Add Subjects Reset
Select Subjects

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
Add Journals Reset
Select Journals

Article Types

remove_circle_outline
Add Article Types Reset
Select Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
Add Countries / Regions Reset
Select Countries / Regions
Update Search
share announcement

Search Results (3)

Search Parameters:
Keywords = pseudocumene

Order results
Result details
Results per page
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
22 pages, 5253 KB  
Article
On the Deactivation Analysis of IM-5 Zeolite in Pseudocumene Methylation with Methanol
by Shumin Hao, Yongrui Wang, Enhui Xing and Xuhong Mu
Crystals 2025, 15(7), 598; https://doi.org/10.3390/cryst15070598 - 25 Jun 2025
Viewed by 949
Abstract
In the methylation of pseudocumene with methanol over IM-5 zeolite, the yield of durene can be enhanced. However, poorer stability of the catalytic activity was observed, especially at a higher methanol/pseudocumene ratio. In this paper, conventional characterization methods (XRD, XRF, TGA, SEM, physical [...] Read more.
In the methylation of pseudocumene with methanol over IM-5 zeolite, the yield of durene can be enhanced. However, poorer stability of the catalytic activity was observed, especially at a higher methanol/pseudocumene ratio. In this paper, conventional characterization methods (XRD, XRF, TGA, SEM, physical adsorption, OH-IR, NH3-TPD, and Py-IR) were used to characterize fresh and deactivated IM-5 zeolite and ZSM-5. FT-IR, XPS, TG-MS, GC-MS, FT-ICR MS, and NMR were employed to characterize deactivated IM-5 zeolite. It was found that the deactivation of IM-5 zeolite was mainly due to the severe coverage of acidic sites and pore channels by carbon deposits. The carbon deposits within the internal surface had a higher abundance, mainly in the form of linear unsaturated chain-like structures with a high degree of unsaturation. The carbon deposits on the external surface were mainly polycyclic aromatic hydrocarbons with alkyl side chains and a high degree of saturation, accompanied by unreacted methanol. Moreover, graphitized carbon existed on both the internal and external surfaces, which made the conventional coke-burning regeneration method unable to restore the activity of the post-reaction IM-5 zeolite. This work had certain reference significance for modulating the acidity and pore channels of zeolite catalysts, thus improving the activity and stability of the catalysts and extending their service life. Full article
(This article belongs to the Section Inorganic Crystalline Materials)
►▼ Show Figures

Figure 1

22 pages, 6072 KB  
Article
Understanding the Effect of IM-5 Zeolite Treated with Hexafluorosilicic Acid for the Methanol Alkylation of Pseudocumene
by Shumin Hao, Yongrui Wang, Enhui Xing and Xuhong Mu
Materials 2025, 18(10), 2252; https://doi.org/10.3390/ma18102252 - 13 May 2025
Cited by 2 | Viewed by 943
Abstract
A study systematically investigating the structural modifications and catalytic performance of IM-5 zeolite treated with hexafluorosilicic acid in pseudocumene alkylation with methanol was carried out. Characterization techniques revealed significant alterations in crystal structure, morphology, textural properties, coordination environment, and acidity induced by the [...] Read more.
A study systematically investigating the structural modifications and catalytic performance of IM-5 zeolite treated with hexafluorosilicic acid in pseudocumene alkylation with methanol was carried out. Characterization techniques revealed significant alterations in crystal structure, morphology, textural properties, coordination environment, and acidity induced by the modifications. Catalytic evaluations demonstrated altered pseudocumene conversion, durene selectivity, and products distribution for optimized samples, with IM-5-0.01 (treated with 0.01 M modifier) showing superior activity stability. The improved performance was attributed to two key factors: a stable framework with high-density medium-strength Brønsted acid sites facilitating complete alkylation and expanded mesoporous volume promoting efficient product diffusion to mitigate deactivation. Conversely, reduced durene selectivity in modified samples stem from intensified isomerization reactions driven by increased external surface area, resulting in higher C9 product fractions. In contrast, the parent IM-5 zeolite exhibited rapid deactivation, with durene selectivity peaking at 40 h before declining. Mechanistic insights revealed dynamic processes including dealumination, defect formation, silicon repair, and aluminum redistribution during treatment, providing a theoretical foundation for rational catalyst design in alkylation reactions. Full article
(This article belongs to the Section Catalytic Materials)
►▼ Show Figures

Figure 1

12 pages, 2737 KB  
Article
Sterical Driving Minor Actinide Selectivity of Bi-pyridyl Diamides: Ortho- vs. Para-Substitution
by Nataliya E. Borisova, Tsagana B. Sumyanova, Alexey V. Ivanov, Anastasia V. Kharcheva, Petr I. Matveev, Svetlana V. Patsaeva and Vladimir G. Petrov
Energies 2022, 15(24), 9497; https://doi.org/10.3390/en15249497 - 14 Dec 2022
Cited by 1 | Viewed by 2021
Abstract
Hybrid donor extractants are a promising class of compounds for the separation of trivalent actinides and lanthanides. In this paper, we present a new ligand from the bipyridyl-dicarboxylic acid diamide family—N,N’-diethyl-N,N’-bis(2,4,5-trimethylphenyl)-[2,2’-bipyridine]-6,6’-dicarboxamide. The synthesis of N-ethyl-2,4,5-trimethylaniline from pseudocumene by selective acetylation is presented. The [...] Read more.
Hybrid donor extractants are a promising class of compounds for the separation of trivalent actinides and lanthanides. In this paper, we present a new ligand from the bipyridyl-dicarboxylic acid diamide family—N,N’-diethyl-N,N’-bis(2,4,5-trimethylphenyl)-[2,2’-bipyridine]-6,6’-dicarboxamide. The synthesis of N-ethyl-2,4,5-trimethylaniline from pseudocumene by selective acetylation is presented. The target ligand was obtained using this aminylene. Chemical synthesis of its complexes with Ln(NO3)3 and their spectroscopic analysis showed that the structure of the complexes is near to the corresponding structures of well-known di-methylated dianilides. A series of studies on the photophysical, complexing, and extraction properties of this ligand and its complexes were carried out. It was shown that the extraction system based on this ligand can selectively isolate americium from the solution of high-level waste imitator. Full article
(This article belongs to the Section A: Sustainable Energy)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying article 1-50 on page 1 of 1.
Back to TopTop