Submit to Catalysts Review for Catalysts Propose a Special Issue

Journal Browser

► Journal Browser

Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Catalysts (ISSN 2073-4344). This special issue belongs to the section "Catalytic Materials".

Deadline for manuscript submissions: closed (31 December 2020) | Viewed by 48242

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special issue Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis book cover image

Share This Special Issue

Special Issue Editor

Dr. Narendra Kumar

E-Mail Website
Guest Editor

Faculty of Science and Engineering, Industrial Chemistry and Reaction Engineering, Åbo Akademi University, Henriksgatan 2, FI-20500 Turku, Finland
Interests: heterogeneous catalysis; catalyst synthesis; nanoporous materials; catalyst characterization; zeolite catalysis; refinery processes; hydrocarbon conversion; reaction mechanism; biomass transformations
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Microporous zeolites and nanoporous materials are important from the academic and industrial research point of view. These inorganic materials have found application as catalysts in several industrial processes in the field of oil refinery, petro-chemical reactions, fine chemicals, drug discovery and pharmaceutical synthesis, exhaust emission control for stationary and mobile engines, and industrial waste water treatment. The reasons for such versatile applications in several industrial processes are the unique properties of microporous zeolites and nanoporous materials, such as uniform pores, channel systems, shape selectivity, resistance to coke formation, thermal and hydrothermal stability. Furthermore, the possibility to tune the amount and strength of Brønsted and Lewis acid sites and the crystal size and to introduce modifications with transition and noble metals are the key to the successful design of efficient, highly selectivity, and stable catalysts. The Special Issue of “Microporous Zeolites and Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis” invites original research papers on the following topics:

Novel zeolite and nanoporous materials synthesis
Advanced technology for catalyst preparation
Design of catalytic active sites
Transition and noble metal modifications
Nanoporous materials crystal engineering
Physico-chemical catalyst characterization
Catalytic applications: Petro-chemicals, Environmental catalysis; Biodiesel, Biofuels from renewables; Fuels and Chemicals from biomass

Dr. Narendra Kumar
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Catalysts is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

Microporous zeolites
Nanoporous materials
Zeolite and nanoporous synthesis
Catalyst preparation
Crystal engineering
Metal modifications
Catalyst characterization: Heterogeneous catalysis, Petro-chemical reactions, Renewables for biofuels

Published Papers (13 papers)

Download All Papers

Editorial

Jump to: Research, Review

3 pages, 149 KiB

Open AccessEditorial

Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Application in Catalysis

by Narendra Kumar

Catalysts 2021, 11(3), 382; https://0-doi-org.brum.beds.ac.uk/10.3390/catal11030382 - 16 Mar 2021

Cited by 2 | Viewed by 1919

Abstract

Microporous zeolites and related nanoporous materials have been studied intensively in academic and industrial laboratories around the world [...] Full article

(This article belongs to the Special Issue Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis)

Research

Jump to: Editorial, Review

17 pages, 5158 KiB

Open AccessArticle

Solvent Influence on Selectivity in α-Pinene Oxide Isomerization Using MoO₃-Modified Zeolite BETA

by Eva Vrbková, Eliška Vyskočilová, Miloslav Lhotka and Libor Červený

Catalysts 2020, 10(11), 1244; https://0-doi-org.brum.beds.ac.uk/10.3390/catal10111244 - 28 Oct 2020

Cited by 11 | Viewed by 2041

Abstract

Natural source turpentine is an available source of α-pinene oxide. This compound’s value is especially given by the possibility of producing important compounds campholenic aldehyde and trans-carveol. In this work, we would like to present the usage of MoO₃-modified zeolite BETA in α-pinene oxide isomerization concerning campholenic aldehyde and trans-carveol formation using a wide range of solvents. Catalyst calcination temperature also influenced the reaction course (selectivity to desired compounds and reaction rate). MoO₃-zeolite BETA was prepared by the wet impregnation method and characterized by different techniques. The use of polar aprotic solvents had the most positive effect on the reaction course. Solvent basicity and polarity considerably influenced the reaction rate and selectivity to particular products. The combination of high basicity and the high polarity was the most suitable for the studied reaction from the reaction rate point of view. Selectivity to campholenic aldehyde and trans-carveol was the most influenced by solvent basicity. Higher solvent basicity caused the preferential formation of trans–carveol, influence on selectivity to campholenic aldehyde formation was the opposite. The described catalyst may be used for α-pinene oxide rearrangement to both desired products dependently on the used solvent. Molybdenum offers an exciting alternative for previously described modifications of zeolites for this reaction. Full article

(This article belongs to the Special Issue Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis)

► Show Figures

Graphical abstract

16 pages, 6115 KiB

Open AccessArticle

CHA-Type Zeolite Prepared by Interzeolite Conversion Method Using FAU and LTL-Type Zeolite: Effect of the Raw Materials on the Crystallization Mechanism, and Physicochemical and Catalytic Properties

by Toshiki Nishitoba, Takuya Nozaki, Sungsik Park, Yong Wang, Junko N. Kondo, Hermann Gies and Toshiyuki Yokoi

Catalysts 2020, 10(10), 1204; https://0-doi-org.brum.beds.ac.uk/10.3390/catal10101204 - 17 Oct 2020

Cited by 19 | Viewed by 3625

Abstract

The effect of the raw materials including parent zeolite as aluminosilicate sources and organic structure-directing agents (OSDAs) on the crystallization mechanism, and physicochemical and catalytic properties of the CHA-type aluminosilicate zeolite was investigated. For this purpose, the FAU-type and the LTL-type zeolites were used as raw material, and trymethyladamantyl ammonium hydroxide and tetraethyl ammonium hydroxide were used as OSDAs. We firstly found that the CHA-type aluminosilicate zeolite was crystallized from the combination of the LTL-type zeolite and tetraethyl ammonium hydroxide as raw materials. The crystallization behaviors were also monitored in detail. The crystallization was delayed by using the LTL-type zeolite as the starting material regardless of the type of OSDA because of the low solubility of the LTL-type zeolite compared to the FAU-type zeolite. We have found that the Al distribution in the CHA framework was dependent on the raw materials. Thus, the prepared CHA-type aluminosilicate zeolite from the LTL-type zeolite exhibited a high thermal stability and catalytic performance in the methanol to olefins reaction. Full article

(This article belongs to the Special Issue Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis)

► Show Figures

Figure 1

24 pages, 6385 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Synthesis and Characterization of Metal Modified Catalysts for Decomposition of Ibuprofen from Aqueous Solutions

by Soudabeh Saeid, Matilda Kråkström, Pasi Tolvanen, Narendra Kumar, Kari Eränen, Markus Peurla, Jyri-Pekka Mikkola, Laurent Maël, Leif Kronberg, Patrik Eklund and Tapio Salmi

Catalysts 2020, 10(7), 786; https://0-doi-org.brum.beds.ac.uk/10.3390/catal10070786 - 14 Jul 2020

Cited by 12 | Viewed by 3386

Abstract

The presence of pharmaceuticals in surface water, drinking water, and wastewater has attracted significant concern because of the non-biodegradability, resistance, and toxicity of pharmaceutical compounds. The catalytic ozonation of an anti-inflammatory pharmaceutical, ibuprofen was investigated in this work. The reaction mixture was analyzed and measured by high-performance liquid chromatography (HPLC). Liquid chromatography-mass spectrometry (LC-MS) was used for the quantification of by-products during the catalytic ozonation process. Ibuprofen was degraded by ozonation under optimized conditions within 1 h. However, some intermediate oxidation products were detected during the ibuprofen ozonation process that were more resistant than the parent compound. To optimize the process, nine heterogeneous catalysts were synthesized using different preparation methods and used with ozone to degrade the ibuprofen dissolved in aqueous solution. The aim of using several catalysts was to reveal the effect of various catalyst preparation methods on the degradation of ibuprofen as well as the formation and elimination of by-products. Furthermore, the goal was to reveal the influence of various support structures and different metals such as Pd-, Fe-, Ni-, metal particle size, and metal dispersion in ozone degradation. Most of the catalysts improved the elimination kinetics of the by-products. Among these catalysts, Cu-H-Beta-150-DP synthesized by the deposition–precipitation process showed the highest decomposition rate. The regenerated Cu-H-Beta-150-DP catalyst preserved the catalytic activity to that of the fresh catalyst. The catalyst characterization methods applied in this work included nitrogen adsorption–desorption, scanning electron microscopy, transmission electron microscopy, and Fourier-transform infrared spectroscopy. The large pore volume and small metal particle size contributed to the improved catalytic activity. Full article

(This article belongs to the Special Issue Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis)

► Show Figures

Graphical abstract

12 pages, 3163 KiB

Open AccessArticle

Selective Formation of Para-Xylene by Methanol Aromatization over Phosphorous Modified ZSM-5 Zeolites

by Xianjun Niu, Kai Wang, Yang Bai, Yi-en Du, Yongqiang Chen, Mei Dong and Weibin Fan

Catalysts 2020, 10(5), 484; https://0-doi-org.brum.beds.ac.uk/10.3390/catal10050484 - 29 Apr 2020

Cited by 18 | Viewed by 3245

Abstract

Phosphorous modified ZSM-5 zeolites were synthesized by incipient wetness impregnation. Their performances for the methanol to aromatics conversion (MTA) were subsequently evaluated and the relationship between the catalyst structure and performance was focused on. The obtained results indicated that the introduction of phosphorous resulted in the modification of the catalyst structure characteristics and acidic properties, i.e., the reduction in the external surface area and micropore volume, the narrowing of the pore size, and the decrease in the quantity and strength of acid sites. As a result, the P/HZSM-5 catalyst exhibited the enhanced selectivity for the para-xylene (PX) in xylene isomers and xylene in aromatics, and their increase degrees were intensified with the increasing P content. The selectivity of PX in X increased from 23.8% to nearly 90% when P content was 5 wt.%. Meanwhile, the selectivity of xylene in aromatics was enhanced from 41.3% to 60.2%. Full article

(This article belongs to the Special Issue Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis)

► Show Figures

Figure 1

25 pages, 6665 KiB

Open AccessArticle

Pt Modified Heterogeneous Catalysts Combined with Ozonation for the Removal of Diclofenac from Aqueous Solutions and the Fate of by-Products

by Soudabeh Saeid, Matilda Kråkström, Pasi Tolvanen, Narendra Kumar, Kari Eränen, Jyri-Pekka Mikkola, Leif Kronberg, Patrik Eklund, Atte Aho, Heikki Palonen, Markus Perula, Andrey Shchukarev and Tapio Salmi

Catalysts 2020, 10(3), 322; https://0-doi-org.brum.beds.ac.uk/10.3390/catal10030322 - 12 Mar 2020

Cited by 8 | Viewed by 2724

Abstract

The degradation of the pharmaceutical compound diclofenac in an aqueous solution was studied with an advanced oxidation method, catalytic ozonation. Diclofenac was destroyed in a few minutes by ozonation but several long-lasting degradation by-products were formed. For this reason, the combination of heterogeneous catalysts and ozonation was applied to eliminate them completely. The kinetics of the diclofenac degradation and the formation of by-products were thoroughly investigated. Loading of Pt on the catalysts resulted in an improvement of the activity. The Mesoporous Molecular Sieves (MCM) were one of the promising catalysts for the degradation of organic pollutants. In this study, six heterogeneous catalysts were screened, primarily MCM-22-100 catalysts with different Pt concentrations loaded via the evaporation-impregnation (EIM) method, and they were applied on the degradation of diclofenac. It was found that the presence of Pt improved the degradation of diclofenac and gave lower concentrations of by-products. The 2 wt % Pt-H-MCM-22-100-EIM demonstrated the highest degradation rate compared to the proton form, 1% or 5 wt % Pt concentration, i.e., an optimum was found in between. Pt-H-Y-12-IE and Pt-γ-Al2O3 (UOP)-IMP catalysts were applied and compared with the MCM-22 structure. Upon use of both of these catalysts, an improvement in the degradation of diclofenac and by-products was observed, and the 2 wt % Pt-H-MCM-22-100-EIM illustrated the maximum activity. All important characterization methods were applied to understand the behavior of the catalysts (X-ray powder diffraction, transmission electron microscopy, nitrogen physisorption, scanning electron microscopy, energy dispersive X-ray micro-analyses, pyridine adsorption-desorption with FTIR spectroscopy, X-ray photoelectron spectroscopy). Finally, leaching of Pt and Al were analyzed by inductively coupled optical emission spectrometry. Full article

(This article belongs to the Special Issue Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis)

► Show Figures

Figure 1

13 pages, 2393 KiB

Open AccessArticle

Catalytic Properties of Microporous Zeolite Catalysts in Synthesis of Isosorbide from Sorbitol by Dehydration

by Sangmin Jeong, Ki-Joon Jeon, Young-Kwon Park, Byung-Joo Kim, Kyong-Hwan Chung and Sang-Chul Jung

Catalysts 2020, 10(2), 148; https://0-doi-org.brum.beds.ac.uk/10.3390/catal10020148 - 23 Jan 2020

Cited by 20 | Viewed by 4253

Abstract

As bisphenol A has been found to cause hormonal disturbances, the natural biomaterial isosorbide is emerging as a substitute. In this study, a method for isosorbide synthesis from sorbitol was proposed by dehydration under high temperature and high pressure reaction. Microporous zeolites and Amberlyst 35 solid acids with various acid strengths and pore characteristics were applied as catalysts. In the synthesis of isosorbide from sorbitol, the acidity of the catalyst was the main factor. MOR and MFI zeolite catalysts with high acid strength and small pore size showed low conversion of sorbitol and low yield of isosorbide. On the other hand, the conversion of sorbitol was high in BEA zeolite with moderate acid strength. Amberlyst 35 solid acid catalysts showed a relatively high conversion of sorbitol, but low yield of isosorbide. The Amberlyst 35 solid acid catalyst without micropores did not show any inhibitory effects on the production of by-products. However, in the BEA zeolite catalyst, which has a relatively large pore structure compared with the MOR and MFI zeolites, the formation of by-products was suppressed in the pores, thereby improving the yield of isosorbide. Full article

(This article belongs to the Special Issue Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis)

► Show Figures

Graphical abstract

20 pages, 5703 KiB

Open AccessFeature PaperArticle

Advanced Oxidation Process for Degradation of Carbamazepine from Aqueous Solution: Influence of Metal Modified Microporous, Mesoporous Catalysts on the Ozonation Process

by Soudabeh Saeid, Matilda Kråkström, Pasi Tolvanen, Narendra Kumar, Kari Eränen, Jyri-Pekka Mikkola, Leif Kronberg, Patrik Eklund, Markus Peurla, Atte Aho, Andrey Shchukarev and Tapio Salmi

Catalysts 2020, 10(1), 90; https://0-doi-org.brum.beds.ac.uk/10.3390/catal10010090 - 07 Jan 2020

Cited by 16 | Viewed by 4090

Abstract

Carbamazepine (CBZ), a widely used pharmaceutical compound, is one of the most detected drugs in surface waters. The purpose of this work was to identify an active and durable catalyst, which, in combination with an ozonation process, could be used to remove CBZ and its degradation products. It was found that the CBZ was completely transformed after ozonation within the first minutes of the treatment. However, the resulting degradation products, 1-(2-benzaldehyde)-4-hydro-(1H,3H)-quinazoline-2-one (BQM) and 1-(2-benzaldehyde)-(1H,3H)-quinazoline-2,4-dione (BQD), were more resistant during the ozonation process. The formation and degradation of these products were studied in more detail and a thorough catalytic screening was conducted to reveal the reaction kinetics of both the CBZ and its degradation products. The work was performed by non-catalytic ozonation and with six different heterogeneous catalysts (Pt-MCM-41-IS, Ru-MCM-41-IS, Pd-H-Y-12-EIM, Pt-H-Y-12-EIM, Pd-H-Beta-300-EIM and Cu-MCM-41-A-EIM) operating at two temperatures 20 °C and 50 °C. The influence of temperature on degradation kinetics of CBZ, BQM and BQD was studied. The results exhibited a notable difference in the catalytic behavior by varying temperature. The higher reactor temperature (50 °C) showed a higher activity of the catalysts but a lower concentration of dissolved ozone. Most of the catalysts exhibited higher removal rate for BQM and BQD compared to non-catalytic experiments in both temperatures. The Pd-H-Y-12-EIM catalyst illustrated a higher degradation rate of by-products at 50 °C compared to other catalysts. Full article

(This article belongs to the Special Issue Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis)

► Show Figures

Figure 1

13 pages, 2638 KiB

Open AccessArticle

Chromium Oxide Supported on Silicalite-1 Zeolite as a Novel Efficient Catalyst for Dehydrogenation of Isobutane Assisted by CO₂

by Yajun Luo, Changxi Miao, Yinghong Yue, Weimin Yang, Weiming Hua and Zi Gao

Catalysts 2019, 9(12), 1040; https://0-doi-org.brum.beds.ac.uk/10.3390/catal9121040 - 07 Dec 2019

Cited by 13 | Viewed by 3288

Abstract

The chromium oxide catalysts supported on silicalite-1 zeolite (Cr/S-1) with a Cr content between 0.5% and 7% were synthesized via an incipient wetness method. The catalysts were characterized by XRD, N₂ adsorption, TEM-EDX, UV-vis, DRIFTS, ²⁹Si MAS NMR, XPS, H₂-TPR, and NH₃-TPD. The optimum 3%Cr/S-1 catalyst with 3%Cr is more active and stable than SBA-15-supported one with the same Cr content, which is a consequence of a higher content of Cr⁶⁺ in the fresh 3%Cr/S-1 catalyst and a higher content of Cr⁶⁺ retained on the former catalyst during the reaction. The 3%Cr/S-1 catalyst affords an isobutane conversion of 36.5% with 71.2% isobutene selectivity. The catalytic activity is well correlated with the content of Cr⁶⁺ in the fresh catalysts. Carbon dioxide displays a promoting effect on the dehydrogenation reaction. Full article

(This article belongs to the Special Issue Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis)

► Show Figures

Graphical abstract

18 pages, 3346 KiB

Open AccessArticle

H-ZSM-5 Materials Embedded in an Amorphous Silica Matrix: Highly Selective Catalysts for Propylene in Methanol-to-Olefin Process

by Huda Sharbini Kamaluddin, Sulaiman Nassir Basahel, Katabathini Narasimharao and Mohamed Mokhtar

Catalysts 2019, 9(4), 364; https://0-doi-org.brum.beds.ac.uk/10.3390/catal9040364 - 17 Apr 2019

Cited by 18 | Viewed by 7463

Abstract

H-ZSM-5 materials embedded in an amorphous silica were successfully synthesized with three different Si/Al ratios (i.e., 40, 45, and 50). The presence of the MFI structure in the synthesized samples was confirmed by X-ray diffraction (XRD), Fourier transform infra-red (FT-IR), and solid state-nuclear magnetic resonance (SSNMR) techniques. The morphology and textural properties of the samples were investigated by scanning electron microscopy (SEM), TEM, and N₂-physisorption measurements. Furthermore, acidic properties of the synthesized catalysts have been studied by NH₃-TPD and FT-IR spectroscopy of CO adsorption studies. Variation of the Si/Al ratio affected the crystal morphology, porosity, and particle size, as well as the strength and distribution of acid sites. The synthesized zeolite materials possessed low acid-site density and exhibited high catalytic activity in the methanol-to-olefin (MTO) reaction. To study the intermediate species responsible for catalyst deactivation, the MTO reaction was carried out at high temperature (500 °C) to accelerate catalyst deactivation. Interestingly, the synthesized catalysts offered high selectivity towards the formation of propylene (C₃₌), in comparison to a commercial microporous crystalline H-ZSM-5 with Si/Al = 40, under the same reaction conditions. The synthesized H-ZSM-5 materials offered a selectivity ratio of C₃₌/C₂₌ 12, while it is around 2 for the commercial H-ZSM-5 sample. The formation of hydrocarbon species during MTO reaction over zeolite samples has been systematically studied with operando UV-vis spectroscopy and online gas chromatography. It is proposed that the strength and type of acid sites of catalyst play a role in propylene selectivity as well as the fast growing of active intermediate species. The effective conversion of methanol into propylene in the case of synthesized H-ZSM-5 materials was observed due to possession of weak acid sites. This effect is more pronounced in H-ZSM-5 sample with a Si/Al ratio of 45. Full article

(This article belongs to the Special Issue Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis)

► Show Figures

Graphical abstract

9 pages, 2004 KiB

Open AccessArticle

Direct Synthesis of Ti-Containing CFI-Type Extra-Large-Pore Zeolites in the Presence of Fluorides

by Yichen Wang, Hongjuan Wang, Yuanchao Shao, Tianduo Li, Takashi Tatsumi and Jin-Gui Wang

Catalysts 2019, 9(3), 257; https://0-doi-org.brum.beds.ac.uk/10.3390/catal9030257 - 14 Mar 2019

Cited by 6 | Viewed by 2790

Abstract

Ti-containing zeolites showed extremely high activity and selectivity in numerous friendly environmental oxidation reactions with hydrogen peroxide as a green oxidant. It will be in high demand to synthesize Ti-containing crystalline extra-large-pore zeolites due to the severe restrictions of medium-pore and/or large-pore zeolites for bulky reactant oxidations. However, the direct synthesis of extra-large-pore Ti-zeolites was still challengeable. Here, we firstly report a strategy to directly synthesize high-performance Ti-containing CFI-type extra-large-pore (Ti-CFI) zeolites assisted with fluorides. The well-crystallized Ti-CFI zeolites with framework titanium species could be synthesized in the hydrofluoric acid system with seed or in the ammonium fluoride system without seed, which showed higher catalytic activity for cyclohexene oxidation than that synthesized from the traditional LiOH system. Full article

(This article belongs to the Special Issue Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis)

► Show Figures

Graphical abstract

15 pages, 5384 KiB

Open AccessArticle

Zn-Co@N-Doped Carbon Derived from ZIFs for High-Efficiency Synthesis of Ethyl Methyl Carbonate: The Formation of ZnO and the Interaction between Co and Zn

by Ya-Nan Miao, Yuan Wang, Dong-Hui Pan, Xiang-Hai Song, Si-Quan Xu, Li-Jing Gao and Guo-Min Xiao

Catalysts 2019, 9(1), 94; https://0-doi-org.brum.beds.ac.uk/10.3390/catal9010094 - 17 Jan 2019

Cited by 13 | Viewed by 4727

Abstract

In this work, a series of Zn-Co@N-doped carbon materials were prepared by pyrolysis of Co/Zn-ZIF precursors under a N₂ atmosphere and used for high-efficiency synthesis of ethyl methyl carbonate (EMC) from dimethyl carbonate (DMC) and diethyl carbonate (DEC). The Co to Zn molar ratio and calcination temperature were varied to study the physical and chemical properties of Zn-Co@N-doped carbon materials identified by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), inductively coupled plasma (ICP), thermogravimetric analysis (TG) and temperature programmed desorption (TPD) analysis. It was deduced that the formation of a ZnO crystalline structure and the interaction between zinc and cobalt providing weak basic sites and strong basic sites, respectively, in different samples significantly affected their catalytic performance. The catalyst activated the reaction most effectively when the Co to Zn molar ratio was 1.0 and calcination temperature was 600 °C. With the DMC to DEC molar ratio controlled at 1:1, a superior yield of around 51.50% of product EMC can be gained over catalyst ZnCo/NC-600 at 100 °C with 1 wt% catalyst loading in 7 h. Full article

(This article belongs to the Special Issue Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis)

► Show Figures

Graphical abstract

Review

Jump to: Editorial, Research

25 pages, 3755 KiB

Open AccessReview

Review on the Macro-Transport Processes Theory for Irregular Pores able to Perform Catalytic Reactions

by Iván Santamaría-Holek, Saúl I. Hernández, Consuelo García-Alcántara and Aldo Ledesma-Durán

Catalysts 2019, 9(3), 281; https://0-doi-org.brum.beds.ac.uk/10.3390/catal9030281 - 19 Mar 2019

Cited by 12 | Viewed by 3636

Abstract

We review and generalize a recent theoretical framework that provides a sound physicochemical basis to describe how volume and surface diffusion are affected by adsorption and desorption processes, as well as by catalytic conversion within the space defined by the irregular geometry of the pores in a material. The theory is based on two single-dimensional mass conservation equations for irregular domains deduced for the volumetric (bulk) and surface mass concentrations. It offers a powerful tool for analyzing and modeling mass transport across porous media like zeolites or artificially build materials, since it establishes how the microscopic quantities that refer to the internal details of the geometry, the flow and the interactions within the irregular pore can be translated into macroscopic variables that are currently measured in experiments. The use of the theory in mass uptake experiments is explained in terms of breakthrough curves and effective mass diffusion coefficients which are explicitly related to the internal geometry of the pores. Full article

(This article belongs to the Special Issue Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis)

► Show Figures

Graphical abstract

Journal Menu

Journal Browser

Microporous Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (13 papers)

Editorial

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI