Catalysts with New Formulations/Structures: Synthesis and Applications

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

Deadline for manuscript submissions: closed (30 November 2022) | Viewed by 14707

Special Issue Editors


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Guest Editor
College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 300014, China
Interests: heterogeneous catalysis; nanomaterials; photocatalysis; electrocatalysis

E-Mail Website
Guest Editor
College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China
Interests: theoretical catalysis; heterogeneous catalysis; homogeneous catalysis

Special Issue Information

Dear Colleagues,

Heterogeneous catalysis by solids plays an important role in the modern chemical industry because the catalysts can accelerate the rates of reactions or change the selectivity of reactions towards different products. In many catalytic reactions, however, the catalysts face problems such as poor activity, low selectivity for desirable products, or/and short life time. Since the performance of catalysts depend strongly on their comopsitions and structures, the design of catalysts with new formulations or/and novel structures is a common way to slove these problems.

In this Special Issue (Catalysts with New Formulations/ Structures: Synthesis and Applications), we will collect work related to the design of catalysts with new compositions and/or novel structures to improve the performance of catalysts. Studies that focus on the theoretical understanding of the structure–performance relationship of solid catalysts are also welcome for submission to this Special Issue.

Prof. Dr. Zongjian Liu
Prof. Dr. Jun Li
Guest Editors

Manuscript Submission Information

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Keywords

  • heterogeneous catalysis
  • hydrogenation
  • electrocatalysis
  • photocatalysis
  • microstructures
  • water splitting

Published Papers (9 papers)

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Research

25 pages, 5837 KiB  
Article
Hybrid Materials Based on Imidazo[4,5-b]porphyrins for Catalytic Oxidation of Sulfides
by Inna A. Abdulaeva, Kirill P. Birin, Remi Chassagnon and Alla Bessmertnykh-Lemeune
Catalysts 2023, 13(2), 402; https://doi.org/10.3390/catal13020402 - 13 Feb 2023
Cited by 4 | Viewed by 1505
Abstract
Heterogenized metalloporphyrin catalysts for oxidation reactions are extensively explored to improve chemical production. In this work, manganese meso-tetraarylporphyrins were immobilized on hydrated mesoporous titanium dioxide (SBET = 705 m2 g−1) through carboxylate or phosphonate anchoring groups separated from [...] Read more.
Heterogenized metalloporphyrin catalysts for oxidation reactions are extensively explored to improve chemical production. In this work, manganese meso-tetraarylporphyrins were immobilized on hydrated mesoporous titanium dioxide (SBET = 705 m2 g−1) through carboxylate or phosphonate anchoring groups separated from the macrocycle by the 2-arylimidazole linker fused across one of the pyrrolic rings of the macrocycle. The element composition of two mesoporous hybrid materials thus obtained were investigated and the integrity of the immobilized complexes was shown by different physicochemical methods. Finally, the catalytic efficiency of the more stable material Mn(TMPIP)/TiO2 with the phosphonate anchor was evaluated in the selective oxidation of sulfides to sulfoxides by molecular oxygen in the presence of isobutyraldehyde (IBA). The heterogenized complex has shown excellent catalytic activity exhibiting a turnover (TON) of ~1100 in a single catalytic run of the sulfoxidation of thioanisole. The catalyst was successfully reused in seven consecutive catalytic cycles. Full article
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11 pages, 2921 KiB  
Article
Promotion Effect of Ce Doping on Catalytic Performance of LaMnO3 for CO Oxidation
by Nan Wang, Shan Wang, Jie Yang, Ping Xiao and Junjiang Zhu
Catalysts 2022, 12(11), 1409; https://doi.org/10.3390/catal12111409 - 10 Nov 2022
Cited by 4 | Viewed by 1254
Abstract
In this paper, Ce-doped La1-xCexMnO3 perovskite catalysts are prepared by the sol–gel method, and the promotion effect of Ce doping on LaMnO3 catalysts for CO oxidation is investigated. The catalysts are characterized by X-ray diffractograms, Raman, [...] Read more.
In this paper, Ce-doped La1-xCexMnO3 perovskite catalysts are prepared by the sol–gel method, and the promotion effect of Ce doping on LaMnO3 catalysts for CO oxidation is investigated. The catalysts are characterized by X-ray diffractograms, Raman, N2 physisorption isotherms, temperature-programed reduction with H2, transmission electron microscopy, and X-ray photoelectron spectroscopy. The results show that the Ce doping greatly improves the catalytic activity of LaMnO3 for CO oxidation. Among the La1-xCexMnO3 catalysts, La0.8Ce0.2MnO3 shows the best CO catalytic activity, with 100% CO conversion obtained at 180 °C. The characteristic results show that the LaMnO3 perovskite phase exists in all Ce-doped catalysts, and the CeO2 crystalline phase begins to appear at x ≥ 0.1. The high activity of La0.8Ce0.2MnO3 for CO oxidation could be that: (1) it possesses large surface area (25.8 m2/g) to contact with reactants; (2) it has a high surface Ce3+/(Ce3+ + Ce4+) ratio of 0.27, which means high content of oxygen vacancies used for O2 adsorption and activation; and (3) it exhibits strong reducibility that is beneficial to CO activation. Full article
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16 pages, 8762 KiB  
Article
A Study of the Degradation of LEV by Transparent PVA/NCD-TiO2 Nanocomposite Films with Enhanced Visible-Light Photocatalytic Activity
by Anhua Jiang, Xinwen Huang, Geshan Zhang and Wanquan Yang
Catalysts 2022, 12(11), 1336; https://doi.org/10.3390/catal12111336 - 01 Nov 2022
Cited by 1 | Viewed by 1113
Abstract
In recent years, antibiotics (such as levofloxacin (LEV)) have been detected widely in the environment. Semiconductor photocatalysis has been recognized as a promising technology for removing pollutants in the environment. In this work, nitrogen and carbon codoped titanium dioxide nano-catalyst (NCD-TiO2) [...] Read more.
In recent years, antibiotics (such as levofloxacin (LEV)) have been detected widely in the environment. Semiconductor photocatalysis has been recognized as a promising technology for removing pollutants in the environment. In this work, nitrogen and carbon codoped titanium dioxide nano-catalyst (NCD-TiO2) was immobilized in polyvinyl alcohol (PVA) matrix to form PVA/NCD-TiO2 films through solution casting and thermal treatment, which exhibited good photocatalytic efficiency for LEV degradation. The results showed that about 42% LEV can be degraded after 2 h in the presence of PVA/NCD-TiO2 nanocomposite film (the weight ratio of NCD-TiO2 to PVA is 8% and thermal treatment is 120 °C) under visible light. Moreover, possible pathways of photocatalytic degradation of LEV according to the detected intermediates are proposed, which provide insight into the degradation mechanism of LEV by using PVA/NCD-TiO2 photocatalytic films. Finally, the synthesized PVA/NCD-TiO2 films exhibited excellent reusability and stability in photocatalysis. This work provides fundamental support for the design of a high-stability, excellent photocatalyst for practical application. Full article
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10 pages, 1670 KiB  
Article
Integrated CO2 Capture and Hydrogenation to Produce Formate in Aqueous Amine Solutions Using Pd-Based Catalyst
by Lichun Li, Xiangcan Chen, Chu Yao and Meng Xu
Catalysts 2022, 12(8), 925; https://doi.org/10.3390/catal12080925 - 21 Aug 2022
Cited by 3 | Viewed by 2050
Abstract
Integrated CO2 capture and hydrogenation to produce formate offers a sustainable approach for reducing carbon dioxide emissions and producing liquid hydrogen carriers (formate) simultaneously. In the current study, three different types of aqueous amine solutions including monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine [...] Read more.
Integrated CO2 capture and hydrogenation to produce formate offers a sustainable approach for reducing carbon dioxide emissions and producing liquid hydrogen carriers (formate) simultaneously. In the current study, three different types of aqueous amine solutions including monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA) were investigated as CO2-capturing and hydrogenation agents in the presence of a Pd/NAC catalyst. The effect of amine structures on the CO2 absorption products and formate yield was investigated thoroughly. It was found that the formate product was successfully produced in the presence of all three aqueous amine solutions, with tertiary amine TEA accounting for the highest formate yield under the same CO2 loadings. This is due to the fact that primary and secondary amine moieties in MEA and DEA are responsible for the formation of CO2 adducts of carbamate and bicarbonate, whereas the tertiary amine moiety in TEA is responsible for the formation of hydrogenation-favorable bicarbonate as the solo CO2 absorption product. A high yield of formate of 82.6% was achieved when hydrogenating 3 M TEA with 0.3 mol CO2/mol amine solution in the presence of a Pd/NAC catalyst. In addition, the physio-chemical properties of the Pd/NAC catalyst analyzed using TEM, XRD and XPS characterization were applied to rationalize the superior catalytic performance of the catalyst. The reaction mechanism of integrated CO2 capture and hydrogenation to produce formate in aqueous amine solutions over Pd/NAC catalyst was proposed as well. Full article
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10 pages, 3219 KiB  
Article
Selective Synthesis of 1,4-Dioxane from Oxirane Dimerization over ZrO2/TiO2 Catalyst at Low Temperature
by Yinan Wang, Qingrong Yu, Lijun Xue, Qingyue Yu and Xinbao Zhu
Catalysts 2022, 12(8), 832; https://doi.org/10.3390/catal12080832 - 29 Jul 2022
Cited by 1 | Viewed by 2179
Abstract
We report a route to produce 1,4-dioxane from oxirane by using ZrO2/TiO2 as catalyst. The composite oxide ZrO2/TiO2 was prepared by a coprecipitation method and the catalytic performance was tested through the synthesis of 1,4-dioxane from oxirane [...] Read more.
We report a route to produce 1,4-dioxane from oxirane by using ZrO2/TiO2 as catalyst. The composite oxide ZrO2/TiO2 was prepared by a coprecipitation method and the catalytic performance was tested through the synthesis of 1,4-dioxane from oxirane in a pipe reactor. The X-ray diffraction (XRD) shows that ZrO2 and TiO2 are in crystal form. When the mass percentage of ZrO2 is 25%, the composite oxide ZrO2/TiO2 presents as an amorphous form. The sample 25%ZrO2/TiO2 exhibits a specific surface area of 269.5 m2·g−1 and pore volume of 1.34 mL·g−1. The catalyst has 670 µmol·g−1 of NH3-TPD acid, and the characterization of ammonia infrared spectroscopy (NH3-FTIR) shows that both Brønsted and Lewis acids are present on the surface of the catalyst. The reaction mechanism was analyzed according to the distribution of product. The test of catalytic performance showed 100.0% conversion of oxirane and 86.2% selectivity of 1,4-dioxane at the optimal operation conditions: atmospheric pressure, reaction temperature 75 °C and gaseous hourly space velocity of 1200.0 h−1. The catalyst exhibits good catalytic performance stability after continuous use for 720 h. Full article
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9 pages, 1221 KiB  
Article
F@d4r, a New Type of Acidic Catalytic Site in Zeolite
by Yukai Zhao, Weichi Liang, Yihan Wang, Yan Tong, Zhanhong Li, Yuqian Liang, Xiaolong Liu and Jiuxing Jiang
Catalysts 2022, 12(8), 809; https://doi.org/10.3390/catal12080809 - 24 Jul 2022
Viewed by 1364
Abstract
As a solid acid, zeolite has been widely used in many fields such as tail gas treatment, petrochemical engineering, and the fine chemical industry. F has been widely used in the synthesis of pure silica or high silica zeolites. To balance the [...] Read more.
As a solid acid, zeolite has been widely used in many fields such as tail gas treatment, petrochemical engineering, and the fine chemical industry. F has been widely used in the synthesis of pure silica or high silica zeolites. To balance the charge of organic structure directing agents (OSDA), F is often found located at the center of the double-4-rings (d4r) of the as-made zeolites. During calcination, fluorine ion is removed with the OSDA. We screened a series of composition building units and found that d4r is capable to retain F in zeolite structure. We introduce the F back after the calcination to create an unprecedented type of acid site, i.e., F@d4r in pure silica zeolites ITQ-12. The F@d4r species is thermal stable up to 300 °C. ITQ-12 with F@d4r shows substantial catalytic activity in Biginelli reaction. Furthermore, the catalytic performance is proved to be positive correlated with the presence of F@d4r, indicating the mild acid catalytic property of F@d4r. Full article
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15 pages, 4700 KiB  
Article
Substituent’s Effects of PNP Ligands in Ru(II)-Catalyzed CO2 Hydrogenation to Formate: Theoretical Analysis Considering Steric Hindrance and Promotion of Hydrogen Bonding
by Xiangyang Feng, Jun Li and Zhuhong Yang
Catalysts 2022, 12(7), 760; https://doi.org/10.3390/catal12070760 - 08 Jul 2022
Cited by 1 | Viewed by 1447
Abstract
This paper investigates the effects of substituents in PNP-type ruthenium complexes in the catalytic hydrogenation of CO2 to formate using the DFT method. Six groups were considered as substituents linked to the P atom of the PNP ligand: hydrogen, methyl, iso-propyl, [...] Read more.
This paper investigates the effects of substituents in PNP-type ruthenium complexes in the catalytic hydrogenation of CO2 to formate using the DFT method. Six groups were considered as substituents linked to the P atom of the PNP ligand: hydrogen, methyl, iso-propyl, tert-butyl, cyclopentyl, and cyclohexyl. The substituent effects were analyzed from the perspectives of steric hindrance and promotion of hydrogen bonding. With the joint functions of steric hindrance and hydrogen bonding promotion during the CO2 coordination step, hydride addition step, and HCOO rotation step, these groups exhibited very different substituent effects. The results showed that the methyl group was the most favorable substituent when the solvent’s effects were not included, as it formed hydrogen bonding with relatively weak steric hindrance. The second favorable substituent was the iso-propyl group, while the tert-butyl group was the most unfavorable one, due to remarkable steric hindrance. When the substituent was cyclopentyl or cyclohexyl, the complex provided a wider open space for the reaction compared with the tert-butyl-substituted complex, because cyclopentyl and cyclohexyl are cyclic groups. Therefore, the principle for choosing the substituent in PNP-type complexes allowing the design of highly efficient catalysts for CO2 hydrogenation indicates that more hydrogen atoms but wider open space are ideal. In addition, the substituent’s effects can be markedly impacted by the solvent used. Full article
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17 pages, 5212 KiB  
Article
Metal Ions (Li, Mg, Zn, Ce) Doped into La2O3 Nanorod for Boosting Catalytic Oxidative Coupling of Methane
by Jing Xiong, Hongbin Yu, Yuechang Wei, Chengshu Xie, Kezhen Lai, Zhen Zhao and Jian Liu
Catalysts 2022, 12(7), 713; https://doi.org/10.3390/catal12070713 - 29 Jun 2022
Cited by 7 | Viewed by 1749
Abstract
A series of La2O3 nanorod catalysts with doping of active metal ions (Li, Mg, Zn and Ce) were synthesized successfully by the hydrothermal method. The La2O3 nanorods show a uniform size with the length of 50–200 nm [...] Read more.
A series of La2O3 nanorod catalysts with doping of active metal ions (Li, Mg, Zn and Ce) were synthesized successfully by the hydrothermal method. The La2O3 nanorods show a uniform size with the length of 50–200 nm and the width of 5–20 nm, and the {110} crystal facet is a preferentially exposed surface. The active metal ions (Li, Mg, Zn and Ce) doped into the lattice of La2O3 nanorods enhance the selectivity of the desired products during oxidative coupling of methane (OCM) and decrease the reaction temperature. Among these catalysts, the Mg-La2O3 catalyst exhibits the best catalytic performance during the OCM reaction, i.e., its selectivity and yield of C2 products at 780 °C is 73% and 21%, respectively. The effect of doped metal ions on catalytic activity for OCM was systematically investigated. Insight into the fabrication strategy and promoting factors of the OCM reaction indicates the potential to further design a high-efficient catalyst in the future. Full article
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20 pages, 8787 KiB  
Article
Undercooling, Thermal Stability, and Application in Exothermic Catalytic Reaction of SiO2 Encapsulated SnZnCu Microspheres
by Haodong Tang, Xiali Zheng, Yun Yu, Jinxin Liang, Yifan Zheng and Zongjian Liu
Catalysts 2022, 12(2), 205; https://doi.org/10.3390/catal12020205 - 09 Feb 2022
Viewed by 1406
Abstract
SiO2 encapsulated SnZnCu microspheres (several micrometers to about 30 μm in diameter) with very low undercooling, narrow freezing/melting range, and high thermal cycling stability have been produced and used as the temperature stabilizer of the packed bed in highly exothermic Fischer–Tropsch reaction. [...] Read more.
SiO2 encapsulated SnZnCu microspheres (several micrometers to about 30 μm in diameter) with very low undercooling, narrow freezing/melting range, and high thermal cycling stability have been produced and used as the temperature stabilizer of the packed bed in highly exothermic Fischer–Tropsch reaction. The core–shell structured SnZnCu@SiO2 microspheres are prepared in a two-step way, namely SnZnCu microspheres are firstly produced via a molten LiCl–KCl–CsCl eutectic-based metal emulsion method, and then a sol–gel approach is employed to coat them with a uniform, anti-leakage SiO2 layer. It is found that raising the amount of Zn to 4.0 at.% is critical for achieving a very low undercooling (<5 °C for SnZn0.04Cux@SiO2 vs. about 84 °C for Sn@SiO2) and a narrow freezing/melting peak width, and both undercooling and peak width are almost unchanged as the Cu content (x) increases from 1.5 to 3.0 at.%. However, their thermal cycling stability depends positively on the amount of Cu and can be remarkably improved when 3.0 at.% Cu is added. The results also show that low undercooling and narrow freezing/melting peak width are associated with the formation of Sn–Zn–Cu ternary eutectic and metastable phase Cu5Zn8, and poor thermal cycling stability of SnZn0.04Cux@SiO2 microspheres with low Cu content is related to the decomposition of Cu5Zn8 during thermal cycling. By embedding thermally stable SnZn0.04Cu0.03@SiO2 microspheres into the Co/SiO2 catalyst for Fischer–Tropsch synthesis, the temperature gradient in the catalyst bed can be significantly reduced by suppressing the formation of hot spots or thermal runaway and thus rapid deactivation of Co catalyst that occurs in the SnZn0.04Cux@SiO2-absent Co/SiO2 catalyst can be avoided. Full article
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