U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PubAg

Main content area

You searched for: Subject "zeolites" Remove constraint Subject: "zeolites"
Start Over

Search

8,166  Search Results

« Previous | 1 - 20 of 8,166 |
Number of results to display per page

Search Results

1. Catalysts for gaseous organic sulfur removal

Author:
Yuxuan Xie; Jiacheng Bao; Xin Song; Xin Sun; Ping Ning; Chi Wang; Fei Wang; Yixing Ma; Maohong Fan; Kai Li
Source:
Journal of hazardous materials 2023 v.442 pp. 130029
ISSN:
0304-3894
Subject:
zeolites,   etc   ; carbon monoxide; catalysts; catalytic activity; desulfurization; methanethiol; sulfur;     Show all 7 Subjects
Abstract:
... Organic sulfur gases (COS, CS₂ and CH₃SH) are widely present in reducing industrial off-gases, and these substances pose difficulties for the recovery of carbon monoxide and other gases. The reaction pathways and reaction mechanisms of organic sulfur on different catalyst surfaces have yet to be fully summarized. The literature shows that many factors, such as catalyst synthesis method, loaded met ...
DOI:
10.1016/j.jhazmat.2022.130029

2. Direct conversion of methane to zeolite-templated carbons, light hydrocarbons, and hydrogen

Author:
Yujie Liu; Elisabet Huertas Osta; Artem S. Poryvaev; Matvey V. Fedin; Alessandro Longo; Alexei Nefedov; Nikolay Kosinov
Source:
Carbon 2023 v.201 pp. 535-541
ISSN:
0008-6223
Subject:
zeolites,   etc   ; carbon; catalysts; chemistry; hydrogen; methane; microscopy; spectroscopy; topology; value added;     Show all 10 Subjects
Abstract:
... Efficient direct valorization of methane to value-added chemicals and materials remains an unsolved challenge for modern chemistry and materials science. In this work, we explored direct non-oxidative conversion of methane to hydrogen, hydrocarbons, and valuable zeolite-templated carbon materials. First, using a set of spectroscopy and microscopy characterization tools, we investigated how the rea ...
DOI:
10.1016/j.carbon.2022.09.050

3. Insights into a novel nitrogen removal process based on simultaneous anammox and denitrification (SAD) following nitritation with in-situ NOB elimination

Author:
Jing Chen; Jia Zeng; Yiran He; Shiquan Sun; Haipeng Wu; Yaoyu Zhou; Zhenguo Chen; Jianhui Wang; Hong Chen
Source:
Journal of environmental sciences (China) 2023 v.125 pp. 160-170
ISSN:
1001-0742
Subject:
zeolites,   etc   ; Comamonadaceae; DNA; anaerobic ammonium oxidation; batch systems; denitrification; nitrogen; total nitrogen; wastewater; wastewater treatment; China;     Show all 11 Subjects
Abstract:
... Simultaneous anammox and denitrification (SAD) is an efficient approach to treat wastewater having a low C/N ratio; however, few studies have investigated a combination of SAD and partial nitritation (PN). In this study, a lab-scale up-flow blanket filter (UBF) and zeolite sequence batch reactor (ZSBR) were continuously operated to implement SAD and PN advantages, respectively. The UBF achieved a ...
DOI:
10.1016/j.jes.2022.01.019

4. Formaldehyde oxidation on Pd/USY catalysts at room temperature: The effect of acid pretreatment on supports

Author:
Xiaofeng Liu; Chunying Wang; Yumin Chen; Qi Qin; Yaobin Li; Hong He
Source:
Journal of environmental sciences (China) 2023 v.125 pp. 811-822
ISSN:
1001-0742
Subject:
zeolites,   etc   ; acid treatment; adsorption; ambient temperature; carbon dioxide; catalytic activity; formaldehyde; formates; hydrochloric acid; oxidation; reaction mechanisms; surface area; China;     Show all 13 Subjects
Abstract:
... The complete catalytic oxidation of formaldehyde (HCHO) to CO₂ and H₂O at room temperature is a green route for indoor HCHO removal. Zeolite is an excellent carrier material for HCHO oxidation due to its large surface area, intricate pores and high adsorption capacity. However, the zeolite-supported noble metal catalysts have currently shown relatively low activity especially at room temperature. ...
DOI:
10.1016/j.jes.2022.02.025

5. Turning an invasive alien species into a valuable biomass: Anaerobic digestion of Rugulopteryx okamurae after thermal and new developed low-cost mechanical pretreatments

Author:
David De la Lama-Calvente; María José Fernández-Rodríguez; Menta Ballesteros; Ángel Rabdel Ruiz-Salvador; Francisco Raposo; José Carlos García-Gómez; Rafael Borja
Source:
Science of the total environment 2023 v.856 pp. 158914
ISSN:
0048-9697
Subject:
zeolites,   etc   ; Fourier transform infrared spectroscopy; Rugulopteryx okamurae; X-ray diffraction; anaerobic digestion; biomass; circular economy; crystal structure; electron microscopy; environment; environmental impact; invasive species; macroalgae; methane; methane production; microstructure; renewable energy sources; Mediterranean Sea;     Show all 18 Subjects
Abstract:
... The invasive alien seaweed Rugulopteryx okamurae (R.o.) has spread quickly through the Mediterranean Sea causing an unprecedented ecological impact. A solution integrated into a circular economy model is needed in order to curb the negative effects of its presence. Anaerobic digestion (AD) is proposed as a feasible process able to transform biomass into renewable energy. Nevertheless, in order to ...
DOI:
10.1016/j.scitotenv.2022.158914

6. Plate-Like ZSM-5 Zeolites as Robust Catalysts for the Cracking of Hydrocarbons

Author:
Weijiong Dai; Lina Zhang; Runze Liu; Guangjun Wu; Naijia Guan; Landong Li
Source:
ACS applied materials & interfaces 2022 v.14 no.9 pp. 11415-11424
ISSN:
1944-8252
Subject:
zeolites,   etc   ; catalytic activity;     Show all 2 Subject
Abstract:
... Zeolites with good acid site accessibility and high diffusion rates are highly desirable catalysts, especially when dealing with bulk molecules. In this work, ZSM-5 zeolites with similar Si/Al ratios but different thicknesses along the b-axis (from ∼30 nm to ∼5 μm), namely, two plate-like ZSM-5 zeolites and two reference zeolites have been prepared and the impacts of b-axis thickness on the surfac ...
DOI:
10.1021/acsami.1c23614

7. Competitive and sequence reactions of typical hydrocarbon molecules in diesel fraction hydrocracking – a theoretical study by DFT calculations

Author:
Ji-Feng Wang; Si-Jia Ding; Shao-Zhong Peng; Zhan-Lin Yang; Yan-Ze Du
Source:
RSC advances 2022 v.12 no.30 pp. 19537-19547
ISSN:
2046-2069
Subject:
zeolites,   etc   ; adsorption; dehydrogenation; protonation;     Show all 4 Subjects
Abstract:
... The molecular structures of hydrocarbon molecules determine the competitive and sequence reactions in the diesel hydrocracking process. In this study, the hydrocracking reactions of typical hydrocarbons with various saturation degrees and molecular weights in diesel fractions synergistically catalyzed by the Ni–Mo–S nanocluster and Al–Si FAU zeolite are investigated. The results show that the two ...
DOI:
10.1039/d1ra09246d

8. One-pot two-step process directly converting biomass-derived carbohydrate to lactide

Author:
Lou Gao; Ke Du; Tianlan Yan; He Li; Di Pan; Yahong Zhang; Yi Tang
Source:
Chemical communications 2022 v.58 no.29 pp. 4627-4630
ISSN:
1364-548X
Subject:
zeolites,   etc   ; lactic acid; sugars;     Show all 3 Subjects
Abstract:
... This study proposed a strategy for the production of lactide from biomass-derived carbohydrate with excellent yield, involving sugar to racemic lactic acid conversion over Sn-containing Beta zeolite and racemic lactic acid to lactide conversion over H-Beta zeolite. Structural characteristics of the resulting lactide and extensive applicability for various substrates are also presented. ...
DOI:
10.1039/d2cc00093h

9. The Structure of Monomeric Hydroxo-Cuᴵᴵ Species in Cu-CHA. A Quantitative Assessment

Author:
Paolo Cleto Bruzzese; Enrico Salvadori; Bartolomeo Civalleri; Stefan Jäger; Martin Hartmann; Andreas Pöppl; Mario Chiesa
Source:
Journal of the American Chemical Society 2022 v.144 no.29 pp. 13079-13083
ISSN:
1520-5126
Subject:
zeolites,   etc   ; hydrogen bonding; ligands;     Show all 3 Subjects
Abstract:
... Using EPR and HYSCORE spectroscopies in conjunction with ab initio calculations, we assess the structure of framework-bound monomeric hydroxo-Cuᴵᴵ in copper-loaded chabazite (CHA). The species is an interfacial distorted square-planar [CuᴵᴵOH(O-8MRs)₃] complex located at eight-membered-ring windows, displaying three coordinating bonds with zeolite lattice oxygens and the hydroxo ligand hydrogen-bo ...
DOI:
10.1021/jacs.2c06037

10. Unstable and Metastable Mesophases Can Assist in the Nucleation of Porous Crystals

Author:
Andressa A. Bertolazzo; Debdas Dhabal; Laura J. S. Lopes; Samantha K. Walker; Valeria Molinero
Source:
Journal of physical chemistry 2022 v.126 no.7 pp. 3776-3786
ISSN:
1932-7455
Subject:
zeolites,   etc   ; crystallization; energy; temperature;     Show all 4 Subjects
Abstract:
... Porous crystals─including zeolites, metal–organic frameworks, and clathrates─are widely used as catalysts and molecular sieves and in energy applications. These materials are synthesized from solution through an intermediate amorphous phase. However, the structural gap between the amorphous and porous crystal phases can lead to large nucleation barriers and difficulties in the control of crystal p ...
DOI:
10.1021/acs.jpcc.1c10611

11. Combined spectroscopic and computational study for optimising catalyst design in hydrocarbon transformations

Author:
Matthew E. Potter; J. J. M. Le Brocq; A. E. Oakley; H. Cavaye; Bart D. Vandegehuchte; Robert Raja
Source:
Chemical communications 2022 v.58 no.76 pp. 10659-10662
ISSN:
1364-548X
Subject:
zeolites,   etc   ; butanes; catalysts; neutrons; spectroscopy;     Show all 5 Subjects
Abstract:
... Molecular interactions of hydrocarbons within the confined pores of heterogeneous catalysts can influence reaction pathways, which play a crucial role in determining the overall efficacy of catalytic transformations. We probe the interactions of n-butane with a solid-acid zeolite, mordenite, combining inelastic neutron scattering with DFT calculations. This reveals that the solid-acid sites within ...
DOI:
10.1039/d2cc02003c

12. SO₂/NO₂ Separation Driven by NO₂ Dimerization on SSZ-13 Zeolite Membrane

Author:
Ziyi Li; Jun Li; Huazhen Rong; Jiayu Zuo; Xiong Yang; Yi Xing; Yingshu Liu; Guangshan Zhu; Xiaoqin Zou
Source:
Journal of the American Chemical Society 2022 v.144 no.15 pp. 6687-6691
ISSN:
1520-5126
Subject:
zeolites,   etc   ; dimerization; molecular weight; temperature;     Show all 4 Subjects
Abstract:
... The molecular state is crucial for precise gas separation using a zeolite membrane, yet the state control remains a big challenge. Herein, we report a NO₂ dimerization facilitated high performance SO₂/NO₂ separation on a SSZ-13 zeolite membrane. The NO₂ dimerization is triggered by temperature and pressure to form N₂O₄ with big molecular size, and N₂O₄ diffusion into the zeolite pore is inhibited ...
DOI:
10.1021/jacs.2c01635

13. Fabrication of b-oriented MFI membranes from MFI nanosheet layers by ammonium sulfate modifier for the separation of butane isomers

Author:
Hammad Saulat; Wensen Song; Jianhua Yang; Tao Yan; Gaohong He; Michael Tsapatsis
Source:
Journal of membrane science 2022 v.658 pp. 120749
ISSN:
0376-7388
Subject:
zeolites,   etc   ; ammonium sulfate; butanes; nanosheets; permeability;     Show all 5 Subjects
Abstract:
... Fabrication of thin and oriented zeolite membrane is highly preferable and challenging, providing the advantage of less resistance and high permeation for efficient molecular separation. MFI zeolite nanosheets serve as the desirable building block for fabricating thin and preferably b-oriented MFI membranes. However, the secondary growth of deposited MFI zeolite nanosheet layer is an indispensable ...
DOI:
10.1016/j.memsci.2022.120749

14. Textural Characterization by Using an Alternative Langmuir Isotherm and a New Thickness Function

Author:
Ruth D. Mojica-Sepúlveda; Luis J. Mendoza-Herrera; Mercedes Muñoz; Myrian C. Tebaldi
Source:
Langmuir 2022 v.38 no.39 pp. 11972-11982
ISSN:
1520-5827
Subject:
zeolites,   etc   ; micropores; models; porosity; sorption isotherms;     Show all 5 Subjects
Abstract:
... Samples with micropores can not be adequately described by using the Langmuir isotherm. The Langmuir expression is obtained by using the monolayer assumption, which is not valid in samples with micropores. Then, we propose to include in the isotherm a corrective parameter related to the sample porosity. We show that the modified isotherm enables us to describe the experimental values for different ...
DOI:
10.1021/acs.langmuir.2c01721

15. Chemical insight into the hydrothermal deposition of Sb₂(S,Se)₃ towards delicate microstructure engineering

Author:
Yuqian Huang; Rongfeng Tang; Gang Wang; Gang Li; Bo Che; Yan Wang; Weitao Lian; Changfei Zhu; Tao Chen
Source:
Journal of materials chemistry A 2022 v.10 no.18 pp. 9892-9901
ISSN:
2050-7496
Subject:
zeolites,   etc   ; antimony; microstructure; nanocrystals; pH; thermogravimetry;     Show all 6 Subjects
Abstract:
... Hydrothermal deposition is an ideal method to fabricate high-efficiency antimony sulfoselenide (Sb₂(S,Se)₃) solar cells due to its simple, eco-friendly and low-cost processing characteristics. This deposition approach has enabled efficiency breakthrough in Sb₂(S,Se)₃ solar cells, while the chemical mechanisms in the deposition and annealing processes remain undiscovered. Here, we reveal that the d ...
DOI:
10.1039/d2ta00893a

16. Zeolite Phase Selectivity Using the Same Organic Structure-Directing Agent in Fluoride and Hydroxide Media

Author:
Santiago Leon; German Sastre
Source:
Journal of physical chemistry 2022 v.126 no.4 pp. 2078-2087
ISSN:
1932-7455
Subject:
zeolites,   etc   ; computer software; energy; physical chemistry;     Show all 4 Subjects
Abstract:
... Force field-based calculations of all-silica zeolites show the role of fluoride as a structure-directing agent (SDA). Calculations of fully packed organic and fluoride SDAs were possible with an updated version of zeoTsda software, based on Monte Carlo+Lattice Energy Minimization. Comparison between fluoride-containing and fluoride-free calculations using the same organic SDA allowed us to predict ...
DOI:
10.1021/acs.jpcc.1c08688

17. Atomic Insight into the Local Structure and Microenvironment of Isolated Co-Motifs in MFI Zeolite Frameworks for Propane Dehydrogenation

Author:
Zhong-Pan Hu; Gangqiang Qin; Jingfeng Han; Wenna Zhang; Nan Wang; Yijun Zheng; Qike Jiang; Te Ji; Zhong-Yong Yuan; Jianping Xiao; Yingxu Wei; Zhongmin Liu
Source:
Journal of the American Chemical Society 2022 v.144 no.27 pp. 12127-12137
ISSN:
1520-5126
Subject:
zeolites,   etc   ; catalytic activity; dehydrogenation; enzymes; oxygen; propane;     Show all 6 Subjects
Abstract:
... Embedding metal species into zeolite frameworks can create framework-bond metal sites in a confined microenvironment. The metals sitting in the specific T sites of zeolites and their crystalline surroundings are both committed to the interaction with the reactant, participation in the activation, and transient state achievement during the whole catalytic process. Herein, we construct isolated Co-m ...
DOI:
10.1021/jacs.2c02636

18. Chemistry-Encoded Convolutional Neural Networks for Predicting Gaseous Adsorption in Porous Materials

Author:
Ting-Hsiang Hung; Zhi-Xun Xu; Dun-Yen Kang; Li-Chiang Lin
Source:
Journal of physical chemistry 2022 v.126 no.5 pp. 2813-2822
ISSN:
1932-7455
Subject:
zeolites,   etc   ; adsorption; carbon dioxide; neural networks; prediction;     Show all 5 Subjects
Abstract:
... Metal–organic frameworks (MOFs) are an emerging class of materials possessing significant potential in separation and storage applications. Identifying optimal candidates from tens of thousands of MOFs that have been reported is a challenging task. To this end, machine learning (ML) represents a promising approach to facilitate the selection of best-performing MOFs. In this study, we propose a sch ...
DOI:
10.1021/acs.jpcc.1c09649

19. Controlling diffusion resistance, selectivity and deactivation of ZSM-5 catalysts by crystal thickness and defects

Author:
Jonas Hedlund; Ming Zhou; Abrar Faisal; Olov G.W. Öhrman; Valeria Finelli; Matteo Signorile; Valentina Crocellà; Mattias Grahn
Source:
Journal of catalysis 2022 v.410 pp. 320-332
ISSN:
0021-9517
Subject:
zeolites,   etc   ; carbon; catalytic activity; gasoline; isomers; methanol;     Show all 6 Subjects
Abstract:
... A systematic investigation of two sets of defect free and defective ZSM-5 crystals with controlled thickness (T) between 30 and 400 nm and of their performances in methanol conversion was reported for the first time in the present work. The defect free ZSM-5 crystals with a thickness of 35 nm are by far the smallest ever reported and displayed superior activity, stability and selectivity to slower ...
DOI:
10.1016/j.jcat.2022.04.013

20. Fabrication of extra–framework Al in ZSM–5 to enhance light olefins production in catalytic cracking of n–pentane

Author:
Xinyu He; Yajie Tian; Longhui Guo; Congzhen Qiao; Guozhu Liu
Source:
Journal of analytical and applied pyrolysis 2022 v.165 pp. 105550
ISSN:
0165-2370
Subject:
zeolites,   etc   ; Lewis acids; catalysts; hydrides; pentane; pyrolysis;     Show all 6 Subjects
Abstract:
... ZSM–5 zeolite catalysts are widely used for catalytic cracking of hydrocarbons to produce light olefins. In this study, secondary addition of Al was introduced in aluminum–silicon zeolites (ZSM–5) by impregnation to modify their acid properties. Characterizations revealed that extra–framework Al (EFAL) formed after calcinations both on the internal and external surface of the catalysts, which prov ...
DOI:
10.1016/j.jaap.2022.105550