Self-assembly of Silicoaluminophosphate Nanocrystals in Biphasic Media with Water-insoluble Structure-directing Agent

2021 ◽  
Author(s):  
Hongxin Ding ◽  
Qiuming Zhou ◽  
Junfen Li ◽  
Kake Zhu ◽  
Weibin Fan
Keyword(s):  
Self Assembly ◽  
Catalytic Performance ◽  
Dominant Effect ◽  
Diffusion Property ◽  
Structure Directing Agent ◽  
And Diffusion

The catalytic performance of silicoaluminophosphates is dependent on their acidity and diffusion property, which can be altered by structure-directing agent (OSDA) as a result of its dominant effect on crystallization....

Positive Role of Synthesis Method and Hard Template on the Catalytic Performance of SAPO-34 in Methanol to Olefin Reaction.

2020 ◽  
Vol 23 ◽  
Author(s):  
Sajjad Rimaz ◽  
Reza Katal
Keyword(s):  
Particle Size ◽  
Synthesis Method ◽  
Catalytic Performance ◽  
Hard Template ◽  
Structure Directing Agent ◽  
Positive Role ◽  
Methanol To Olefin ◽  
Dg Method ◽  
Synthesis Procedure

: In the present study, SAPO-34 particles were synthesized using hydrothermal (HT) and dry gel (DG) conversion methods in the presence of diethyl amine (DEA) as an organic structure directing agent (SDA). Carbon nanotubes (CNT) were used as hard template in the synthesis procedure to introduce transport pores into the structures of the synthesized samples. The synthesized samples were characterized with different methods to reveal effects of synthesis method and using hard template on their structure and catalytic performance in methanol to olefin reaction (MTO). DG conversion method results in smaller particle size in comparison with hydrothermal method, resulting in enhancing catalytic performance. On the other side, using CNT in the synthesis procedure with DG method results in more reduction in particle size and formation of hierarchical structure which drastically improves catalytic performance.

Effect of Preparation Methods of HPW/SiO2 Mesoporous Composites on its Catalytic Performance in Fuel Oils Desulfurization

2010 ◽  
Vol 148-149 ◽  
pp. 924-928
Author(s):  
Xue Min Yan ◽  
Yuan Zhu Mi
Keyword(s):  
Catalytic Activity ◽  
Self Assembly ◽  
Electrostatic Force ◽  
Oxidative Desulfurization ◽  
Strong Acid ◽  
Catalytic Performance ◽  
Synthesis Mechanism ◽  
Base Interaction ◽  
Preparation Methods ◽  
Oh Groups

Two kinds of mesoporous HPW/SiO2 composites, which have been synthesized respectively by the amino-functionalized (AF) method and evaporation-induced self-assembly (EISA) method, have been used as catalysts in the oxidative desulfurization process of dibenzothiophene(DBT). The catalytic performance results show that the catalyst synthesized by EISA method holds higher catalytic activity than that synthesized by the AF method. The difference of catalytic activity can be attributed to the different synthesis mechanism of two kinds of composites. In the AF method, the bonding force between HPW and SiO2 is strong acid-base interaction, which damages the Keggin structure. Whereas in the EISA process, electrostatic force and hydrogen bonds between W=O groups and Si-OH groups are main bonding forces. The hydrogen bond holds the electron-withdrawing effect, which increases the activity of nonbonding W=O groups in HPW and then results in the enhancement of the catalytic activity.

scholarly journals Effect of boron incorporation on the bioactivity, structure, and mechanical properties of ordered mesoporous bioactive glasses

2020 ◽  
Vol 8 (7) ◽  
pp. 1456-1465 ◽  
Author(s):  
Leonie Deilmann ◽  
Oliver Winter ◽  
Bianca Cerrutti ◽  
Henrik Bradtmüller ◽  
Christopher Herzig ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Self Assembly ◽  
Sol Gel ◽  
Bioactive Glasses ◽  
Structure Directing Agent ◽  
Structural Investigations ◽  
Ordered Mesoporous ◽  
Evaporation Induced Self Assembly

B2O3 doped (0.5–15 mol%) ordered mesoporous bioactive glasses were synthesized via sol–gel based evaporation-induced self-assembly using P123 as a structure directing agent and characterized by biokinetic, mechanical and structural investigations.

scholarly journals Designing a Mesoporous Zeolite Catalyst for Products Optimizing in n-Decane Hydrocraking

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 766 ◽  
Author(s):  
Li Tan ◽  
Xiaoyu Guo ◽  
Xinhua Gao ◽  
Noritatsu Tsubaki
Keyword(s):  
Mass Transfer ◽  
Active Sites ◽  
Zeolite Catalyst ◽  
Catalytic Performance ◽  
Hydrogen Spillover ◽  
Mesoporous Zeolite ◽  
Mesoporous Catalyst ◽  
Hydrogen Atoms ◽  
Effect Factors ◽  
And Diffusion

Mesoporous ZSM-5 zeolite is developed to enhance the catalytic performance in a hydrocracking reaction. The generated mesopores and mesoporous channels in the new catalyst supply more opportunities for reactant accessing the active sites according to the better mass transfer and diffusion. Meanwhile, the acidity of the mesoporous catalyst is also weakened because of the removal of Si and Al species from its MFI structure, which makes the products distribution drift to more valued chemicals such as olefins. In the modified mesoporous ZSM-5 zeolites via different metallic promoters, the olefins’ selectivity increases as the alkalinity of the catalyst increases. The reason for this is that the formed olefins will be further hydrogenated into corresponding alkanes immediately over the extremely acidic zeolite catalyst. Hence, the moderate alkalinity will limit this process, while at the same time the remaining olefins products will too. Furthermore, the Pd-based mesoporous ZSM-5 zeolite shows an excellent n-decane conversion and high propane selectivity due to the occurrence of hydrogen spillover via the Pd promoter. The phenomenon of hydrogen spillover supplies more chemisorbed sites of hydrogen atoms for hydrocracking and hydrogenating in this reaction. In short, this study explores the important effect factors in n-decane hydrocracking reaction activity and products distribution. It also shows a potential for the further industrial application of petroleum-derived fuel hydrocracking according to the optimized products distribution under metallic promoted mesoporous zeolite.

Enhanced Catalytic Performance of the FCC Catalyst with an Alumina Matrix Modified by the Zeolite Y Structure-Directing Agent

2019 ◽  
Vol 58 (14) ◽  
pp. 5455-5463
Author(s):  
Mengjie Xie ◽  
Yifang Li ◽  
Ubong Jerome Etim ◽  
He Lou ◽  
Wei Xing ◽  
...  
Keyword(s):  
Zeolite Y ◽  
Catalytic Performance ◽  
Alumina Matrix ◽  
Structure Directing Agent ◽  
Fcc Catalyst

Formation of microns long thin wire networks with a controlled spatial distribution of elements

2020 ◽  
Vol 10 (7) ◽  
pp. 2020-2028
Author(s):  
Long Pu ◽  
Hua Fan ◽  
Vivek Maheshwari
Keyword(s):  
Spatial Distribution ◽  
Self Assembly ◽  
Catalytic Performance ◽  
Assembly Process ◽  
Thin Wire ◽  
Distribution Of Elements

By controlling the spatial distribution of elements using a simple self-assembly process, the catalytic performance can be enhanced.

EFFECT OF NICKEL CONTENTS ON THE MICROSTRUCTURE OF MESOPOROUS NICKEL OXIDE/GADOLINIUM-DOPED CERIA

2013 ◽  
Vol 06 (06) ◽  
pp. 1350055 ◽  
Author(s):  
SEUNGHYUN AHN ◽  
HYUN KOO ◽  
SUNG-HWAN BAE ◽  
CHAN PARK ◽  
GUYOUNG CHO ◽  
...  
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Self Assembly ◽  
Specific Area ◽  
Mesoporous Structure ◽  
Growth Behavior ◽  
Solid Oxide ◽  
Nano Particles ◽  
Pluronic F127 ◽  
Doped Ceria ◽  
Structure Directing Agent

The effect of NiO contents on the microstructure of mesoporous NiO - Gd 0.25 Ce 0.75 O 2-x ( NiO -GDC) composite for intermediate temperature solid oxide fuel cells (IT-SOFC) was investigated. Mesoporous NiO -GDC powders with different NiO contents were synthesized by self-assembly hydrothermal method using tri-block copolymer, Pluronic F127, as a structure directing agent. Grain growth/agglomeration behaviors of NiO particles and changes of mesoporous structure of GDC particles were characterized by microstructural analyses. NiO -GDC powders were composed of GDC nano particles with ordered mesopore inside the particles and octahedral NiO grains with truncated-edges. As the amount of NiO increases, specific area value of mesoporous NiO -GDC was decreased, and the agglomeration/growth behavior of NiO grains was accelerated.

Ordered mesoporous crystalline aluminas from self-assembly of ABC triblock terpolymer–butanol–alumina sols

RSC Advances ◽  
2015 ◽  
Vol 5 (61) ◽  
pp. 49287-49294 ◽  
Author(s):  
Kwan Wee Tan ◽  
Hiroaki Sai ◽  
Spencer W. Robbins ◽  
Jörg G. Werner ◽  
Tobias N. Hoheisel ◽  
...  
Keyword(s):  
Self Assembly ◽  
One Pot ◽  
Structure Directing Agent ◽  
One Pot Synthesis ◽  
Ordered Mesoporous

One-pot synthesis of periodically mesostructured γ-alumina using an ABC triblock terpolymer as structure-directing agent and in situ derived rigid carbon scaffold.

Catalytic Activity of Fe-SBA-15 Prepared by Evaporation-Induced Self-Assembly (EISA) Method

2017 ◽  
Vol 898 ◽  
pp. 1916-1922
Author(s):  
Tie Ming Zhang ◽  
De Yong Li ◽  
Wen Liu
Keyword(s):  
Catalytic Activity ◽  
Self Assembly ◽  
Cost Effective ◽  
Product Yield ◽  
Bet Surface Area ◽  
Phenol Hydroxylation ◽  
Structure Directing Agent ◽  
Pluronic P123 ◽  
Fe Content ◽  
Evaporation Induced Self Assembly

Fe-SBA-15 materials with different Fe content have been prepared using tetraethyl orthosilicate (TEOS) and iron nitrate (Fe (NO3)3·H2O as precursors and Pluronic P123 as structure directing agent through evaporation-induced self-assembly (EISA) method. The materials were characterized by nitrogen sorption, powder X-ray diffraction and TEM. All the Fe-SBA-15 samples appeared ordered 2D hexagonal mesostructure. The BET surface area and pore diameter were about 500 m2/g and 4 nm respectively. In the reaction of phenol hydroxylation to dihydroxybenzenes, the Fe-SBA-15 materials showed good catalytic activity, giving 20.2% of phenol conversion, 58.2% of selectivity for o-dihydroxy benzene and 41.8% of selectivity for p-dihydroxy benzene. After five cycles, the product yield was 25.2%, while selectivities of o-dihydroxy benzene and p-dihydroxy benzene were 58.2% and 41.8%, respectively. All these findings indicated the potential of Fe-SBA-15-10 could be used as a cost-effective, environment-friendly catalyst.

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