Special Issue "Active Sites in Catalytic Reaction"

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

Deadline for manuscript submissions: closed (31 August 2018)

Special Issue Editor

Guest Editor
Prof. Zhenmeng Peng

University of Akron, Department of Chemical and Biomolecular Engineering, Akron, OH 44325 USA
Website | E-Mail
Interests: catalytic structures; heterogeneous catalysis; electrocatalysis; nanomaterials; energy

Special Issue Information

Dear Colleagues,

Catalysts, capable of promoting reaction kinetics and improving product selectivity, play an essential role in modern industrialized world. The past century has witnessed great successes in catalyst development, with many types of catalyst materials being developed and applied in different fields including economic chemical and petrochemical production, efficient energy generation, and environmental control. However most of these previous successes largely relied on trial-and-error experiments rather than theoretical guidance. This was because of experimental difficulty in identifying the active sites and determining the reaction pathways, both of which serve as important basis for rational catalyst search. With technological advances in characterization approaches and computational chemistry in recent years, identification of active sites and elucidation of catalysis mechanisms become possible and would lead to a new era in catalyst research. This Special Issue aims to cover recent progress and research efforts in identifying, creating and characterizing active sites in catalytic reaction and in elucidating and theoretically understanding catalysis on active sites. All experimental and theoretical works falling into the scope of this Special Issue, including original research papers, short communications, review articles, and perspective articles, are invited for submission.

Prof. Zhenmeng Peng
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 papers will be 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 1300 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

  • Active site
  • Catalyst development
  • Reaction mechanism
  • Heterogeneous catalysis
  • Homogeneous catalysis
  • Enzyme catalysis
  • Electrocatalysis
  • Photoelectrocatalysis
  • Photocatalysis
  • Density functional theory

Published Papers (9 papers)

View options order results:
result details:
Displaying articles 1-9
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle Two-Dimensional Mn-Co LDH/Graphene Composite towards High-Performance Water Splitting
Catalysts 2018, 8(9), 350; https://doi.org/10.3390/catal8090350
Received: 24 July 2018 / Revised: 23 August 2018 / Accepted: 23 August 2018 / Published: 28 August 2018
PDF Full-text (3029 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The oxygen evolution reaction (OER) is a complex multi-step four-electron process showing sluggish kinetics. Layered double hydroxides (LDH) were reported as promising catalysts for the OER, but their low electrical conductivity restricts their widespread applications. To overcome this problem, a composite material containing
[...] Read more.
The oxygen evolution reaction (OER) is a complex multi-step four-electron process showing sluggish kinetics. Layered double hydroxides (LDH) were reported as promising catalysts for the OER, but their low electrical conductivity restricts their widespread applications. To overcome this problem, a composite material containing Mn-Co LDH ultrathin nanosheet and highly conductive graphene was synthesized for the first time. Benefited from the high electrocatalytic activity and the superior charge transfer ability induced by these components, the new material shows superior OER activity. Used as the OER catalyst, a high current density of 461 mA cm−2 at 2.0 V vs. RHE (reversible hydrogen electrode) was measured besides shows a low overpotential of 0.33 V at 10 mA cm−2. Moreover, the new composite also shows a superior bifunctional water splitting performance as catalyst for the OER and HER (hydrogen evolution reaction) catalysts. Our results indicate that the presented material is a promising candidate for water splitting which is cheap and efficient. Full article
(This article belongs to the Special Issue Active Sites in Catalytic Reaction)
Figures

Graphical abstract

Open AccessArticle Design of Specific Acid-Base-Properties in CeO2-ZrO2-Mixed Oxides via Templating and Au Modification
Catalysts 2018, 8(9), 358; https://doi.org/10.3390/catal8090358
Received: 9 August 2018 / Revised: 23 August 2018 / Accepted: 24 August 2018 / Published: 27 August 2018
PDF Full-text (6062 KB) | HTML Full-text | XML Full-text
Abstract
Ceria-zirconia mixed oxides and gold supported oxides exhibit very good thermal stability and catalytic activity, as well as great selectivity. This work has been focused on the controlled synthesis and characterization of cationic- and amphiphilic-templated ceria, zirconia, and ceria-zirconia mixed oxides from nitrate
[...] Read more.
Ceria-zirconia mixed oxides and gold supported oxides exhibit very good thermal stability and catalytic activity, as well as great selectivity. This work has been focused on the controlled synthesis and characterization of cationic- and amphiphilic-templated ceria, zirconia, and ceria-zirconia mixed oxides from nitrate and iso-propoxide precursors, and ceria-zirconia mixed oxides modified with gold via the deposition precipitation method with urea. The characterization of the acidic and basic properties was carried out through two test reactions. A complete chemical and structural characterization of the materials was done using Atomic Absorption Spectroscopy (AAS), Brunauer-Emmet-Teller Surface Analysis (N2-BET), X-Ray Diffraction (XRD), NH3- Temperature Programmed Desorption (TPD)/CO2-TPD, and Fourier Transform Infrared Spectroscopy (FTIR). Template techniques led to the formation of high surface area mesoporous materials with high activity and thermal stability. In general, the acid sites density was decreased, whereas the basic site density was increased by modification with Au or incorporation of zirconia in case of mixed oxides. Full article
(This article belongs to the Special Issue Active Sites in Catalytic Reaction)
Figures

Graphical abstract

Open AccessArticle Active Site of O2 and Its Improvement Mechanism over Ce-Ti Catalyst for NH3-SCR Reaction
Catalysts 2018, 8(8), 336; https://doi.org/10.3390/catal8080336
Received: 8 July 2018 / Revised: 3 August 2018 / Accepted: 6 August 2018 / Published: 17 August 2018
PDF Full-text (1943 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The current study on Ce-Ti catalyst was mainly focused on the function of NH3 and NO adsorption sites. In our study, by comparing Ce-Ti (doped catalyst) to Ce/Ti (supported catalyst), the active site of O2 and its improvement mechanism over Ce-Ti
[...] Read more.
The current study on Ce-Ti catalyst was mainly focused on the function of NH3 and NO adsorption sites. In our study, by comparing Ce-Ti (doped catalyst) to Ce/Ti (supported catalyst), the active site of O2 and its improvement mechanism over Ce-Ti catalyst for NH3-Selective catalytic reduction (SCR) reactions were investigated. For Ce-Ti catalyst, a cerium atom was confirmed entering a TiO2 crystal lattice by X-ray diffraction (XRD) and Raman; the structure of Ce-□-Ti (□ represents oxygen vacancy) in Ce-Ti catalyst was confirmed by X-ray photoelectron spectroscopy (XPS) and Photoluminescence spectra (PL spectra). The nature of this structure was characterized by electron paramagnetic resonance (EPR), Ammonia temperature-programmed desorption (NH3-TPD), hydrogen temperature-programmed reduction (H2-TPR), Nitric oxide temperature-programmed desorption (NO-TPD) and In situ DRIFT. The results indicated that oxygen vacancies had a promotive effect on the adsorption and activation of oxygen, and oxygen was converted to superoxide ions in large quantities. Also, because of adsorption and activation of NO and NH3, electrons were transferred to adsorbed oxygen via oxygen vacancies, which also promoted the formation of superoxide ions. We expected that our study could promote understanding of the active site of O2 and its improvement mechanism for doped catalyst. Full article
(This article belongs to the Special Issue Active Sites in Catalytic Reaction)
Figures

Graphical abstract

Open AccessArticle Clarification of Active Sites at Interfaces between Silica Support and Nickel Active Components for Carbon Monoxide Methanation
Catalysts 2018, 8(7), 293; https://doi.org/10.3390/catal8070293
Received: 13 June 2018 / Revised: 15 July 2018 / Accepted: 16 July 2018 / Published: 20 July 2018
Cited by 1 | PDF Full-text (4450 KB) | HTML Full-text | XML Full-text
Abstract
Identification of active site is critical for developing advanced heterogeneous catalysis. Here, a nickel/silica (Ni/SiO2) catalyst was prepared through an ammonia-evaporation method for CO methanation. The as-obtained Ni/SiO2 catalyst shows a CO conversion of 96.74% and a methane selectivity of
[...] Read more.
Identification of active site is critical for developing advanced heterogeneous catalysis. Here, a nickel/silica (Ni/SiO2) catalyst was prepared through an ammonia-evaporation method for CO methanation. The as-obtained Ni/SiO2 catalyst shows a CO conversion of 96.74% and a methane selectivity of 93.58% at 623 K with a weight hourly space velocity of 25,000 mL·g−1·h−1. After 150 h of continuous testing, the CO conversion still retains 96%, which indicates a high catalyst stability and long life. An in situ vacuum transmission infrared spectrum demonstrates that the main active sites locate at the interface between the metal Ni and the SiO2 at a wave number at 2060 cm−1 for the first time. The interesting discovery of the active site may offer a new insight for design and synthesis of methanation catalysts. Full article
(This article belongs to the Special Issue Active Sites in Catalytic Reaction)
Figures

Graphical abstract

Open AccessArticle Prickly Pear-Like Three-Dimensional Porous MoS2: Synthesis, Characterization and Advanced Hydrogen Evolution Reaction
Catalysts 2018, 8(6), 235; https://doi.org/10.3390/catal8060235
Received: 8 April 2018 / Revised: 28 May 2018 / Accepted: 29 May 2018 / Published: 4 June 2018
PDF Full-text (1911 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Herein, we hydrothermally synthesize a type of prickly pear-like three-dimensional (3D) porous MoS2 (ZT-MoS2), using a zinc oxide (ZnO) rod deposited on quartz glass substrates, as a template for an advanced hydrogen evolution reaction (HER) catalyst. Microscopic and spectroscopic tools
[...] Read more.
Herein, we hydrothermally synthesize a type of prickly pear-like three-dimensional (3D) porous MoS2 (ZT-MoS2), using a zinc oxide (ZnO) rod deposited on quartz glass substrates, as a template for an advanced hydrogen evolution reaction (HER) catalyst. Microscopic and spectroscopic tools comprehensively characterize the morphology of the ZT-MoS2 nanostructure, which exhibits adequate edge active sites and defects, as well as a high component of active octahedral MoS2 (1T-MoS2). Electrochemical characterizations reveal the good HER performance of the ZT-MoS2 that presents a good overpotential of 110 mV, and a Tafel slope of 63 mV·dec−1, superior to most of the previously reported MoS2-based HER catalysts. This work contributes to the design and fabrication of 3D MoS2 with enhanced HER performance, which holds great promise for fuel cells and energy conversion. Full article
(This article belongs to the Special Issue Active Sites in Catalytic Reaction)
Figures

Figure 1

Open AccessArticle Nitrogen-Doped Porous Carbon Derived from Bamboo Shoot as Solid Base Catalyst for Knoevenagel Condensation and Transesterification Reactions
Catalysts 2018, 8(6), 232; https://doi.org/10.3390/catal8060232
Received: 30 April 2018 / Revised: 27 May 2018 / Accepted: 29 May 2018 / Published: 4 June 2018
PDF Full-text (4361 KB) | HTML Full-text | XML Full-text
Abstract
Highly porous nitrogen-doped carbons derived from bamboo shoots (BSNCs) were prepared through an in-situ synthesis method. The results showed that BSNCs had a large specific surface area, a relatively high nitrogen content and hierarchically porous structures. The catalytic properties of BSNCs were evaluated
[...] Read more.
Highly porous nitrogen-doped carbons derived from bamboo shoots (BSNCs) were prepared through an in-situ synthesis method. The results showed that BSNCs had a large specific surface area, a relatively high nitrogen content and hierarchically porous structures. The catalytic properties of BSNCs were evaluated based on Knoevenagel condensation and transesterification reactions. Deprotonated BSNC-700 exhibited high efficiency for the model reactions as a solid base catalyst, and the superior sample deprotonated in tBuOK solution with a concentration of 0.1 increased the conversion rate from 16.1% to 76.0% for Knoevenagel condensation. The two reactions proceeded smoothly in the presence of deprotonated BSNC-700. The results also showed that the catalyst could be recycled for several times for Knoevenagel condensation. The results from this research will provide a guideline to develop bamboo shoot as a precursor to fabricate a superb solid base catalyst. Full article
(This article belongs to the Special Issue Active Sites in Catalytic Reaction)
Figures

Figure 1

Open AccessArticle Single-Atom Mn Active Site in a Triol-Stabilized β-Anderson Manganohexamolybdate for Enhanced Catalytic Activity towards Adipic Acid Production
Catalysts 2018, 8(3), 121; https://doi.org/10.3390/catal8030121
Received: 5 February 2018 / Revised: 10 March 2018 / Accepted: 14 March 2018 / Published: 19 March 2018
Cited by 1 | PDF Full-text (2366 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Adipic acid is an important raw chemical for the commercial production of polyamides and polyesters. The traditional industrial adipic acid production utilizes nitric acid to oxidize KA oil (mixtures of cyclohexanone and cyclohexanol), leading to the emission of N2O and thus
[...] Read more.
Adipic acid is an important raw chemical for the commercial production of polyamides and polyesters. The traditional industrial adipic acid production utilizes nitric acid to oxidize KA oil (mixtures of cyclohexanone and cyclohexanol), leading to the emission of N2O and thus causing ozone depletion, global warming, and acid rain. Herein, we reported an organically functionalized β-isomer of Anderson polyoxometalates (POMs) nanocluster with single-atom Mn, β-{[H3NC(CH2O)3]2MnMo6O18} (1), as a highly active catalyst to selectively catalyze the oxidation of cyclohexanone, cyclohexanol, or KA oil with atom economy use of 30% H2O2 for the eco-friendly synthesis of adipic acid. The catalyst has been characterized by single crystal and powder XRD, XPS, ESI-MS, FT-IR, and NMR. A cyclohexanone (cyclohexanol) conversion of >99.9% with an adipic acid selectivity of ~97.1% (~85.3%) could be achieved over catalyst 1 with high turnover frequency of 2427.5 h−1 (2132.5 h−1). It has been demonstrated that the existence of Mn3+ atom active site in catalyst 1 and the special butterfly-shaped topology of POMs both play vital roles in the enhancement of catalytic activity. Full article
(This article belongs to the Special Issue Active Sites in Catalytic Reaction)
Figures

Graphical abstract

Open AccessArticle The H2-Treated TiO2 Supported Pt Catalysts Prepared by Strong Electrostatic Adsorption for Liquid-Phase Selective Hydrogenation
Catalysts 2018, 8(2), 87; https://doi.org/10.3390/catal8020087
Received: 15 January 2018 / Revised: 2 February 2018 / Accepted: 6 February 2018 / Published: 22 February 2018
Cited by 1 | PDF Full-text (2406 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The H2-treated TiO2 supported Pt catalysts were prepared by strong electrostatic adsorption method and tested in the liquid-phase selective hydrogenation of various organic compounds such as 3-nitrostyrene to vinylaniline (VA) and furfural to furfuryl alcohol (FA). A combination of high
[...] Read more.
The H2-treated TiO2 supported Pt catalysts were prepared by strong electrostatic adsorption method and tested in the liquid-phase selective hydrogenation of various organic compounds such as 3-nitrostyrene to vinylaniline (VA) and furfural to furfuryl alcohol (FA). A combination of high Pt dispersion, strong interaction of Pt-TiOx, and the presence of low coordination Pt sites was necessary for high hydrogenation activity. However, while the selectivity of VA in 3-nitrostyrene hydrogenation did not depend much on the catalyst preparation method used, the selectivity of FA in furfural hydrogenation was much higher when the catalysts were prepared by SEA, comparing to those obtained by impregnation in which the solvent product was formed, due probably to the non-acidic conditions used during Pt loading by SEA method. Full article
(This article belongs to the Special Issue Active Sites in Catalytic Reaction)
Figures

Graphical abstract

Review

Jump to: Research

Open AccessReview Covalent Organic Frameworks: Promising Materials as Heterogeneous Catalysts for C-C Bond Formations
Catalysts 2018, 8(9), 404; https://doi.org/10.3390/catal8090404
Received: 28 August 2018 / Revised: 13 September 2018 / Accepted: 15 September 2018 / Published: 19 September 2018
PDF Full-text (30917 KB) | HTML Full-text | XML Full-text
Abstract
Covalent organic frameworks (COFs) are defined as highly porous and crystalline polymers, constructed and connected via covalent bonds, extending in two- or three-dimension. Compared with other porous materials such as zeolite and active carbon, the versatile and alternative constituent elements, chemical bonding types
[...] Read more.
Covalent organic frameworks (COFs) are defined as highly porous and crystalline polymers, constructed and connected via covalent bonds, extending in two- or three-dimension. Compared with other porous materials such as zeolite and active carbon, the versatile and alternative constituent elements, chemical bonding types and characteristics of ordered skeleton and pore, enable the rising large family of COFs more available to diverse applications including gas separation and storage, optoelectronics, proton conduction, energy storage and in particular, catalysis. As the representative candidate of next-generation catalysis materials, because of their large surface area, accessible and size-tunable open nano-pores, COFs materials are suitable for incorporating external useful active ingredients such as ligands, complexes, even metal nanoparticles deposition and substrate diffusion. These advantages make it capable to catalyze a variety of useful organic reactions such as important C-C bond formations. By appropriate pore-engineering in COFs materials, even enantioselective asymmetric C-C bond formations could be realized with excellent yield and ee value in much shorter reaction time compared with their monomer and oligomer analogues. This review will mainly introduce and discuss the paragon examples of COFs materials for application in C-C bond formation reactions for the organic synthetic purpose. Full article
(This article belongs to the Special Issue Active Sites in Catalytic Reaction)
Figures

Figure 1

Back to Top