Song Zou, Zheng Wang, Yizhou Wang, Yanping Ma, Yang Sun, Wen-Hua Sun
In this study, 2-t-butyl-4-arylimino-2,3-dihydroacridylnickel dibromides were synthesized by nickel-template one-pot condensation, and well characterized along with the single-crystal X-ray diffraction to one representative complex, revealing a distorted tetrahedral geometry around nickel. When activated with modified methylaluminoxane (MMAO), all nickel complexes exhibited high activities (up to 1.91 × 106 g mol−1 (Ni) h−1) toward major trimerization of ethylene. When activated with ethylaluminum dichloride (EtAlCl2), however, the title complexes performed good activities (up to 1.05 × 106 g mol−1 (Ni) h−1) for selective dimerization of ethylene. In comparison to analogous nickel complexes, higher activities were achieved with the substituent of t-butyl group, especially in the rare case of nickel complexes performing trimerization of ethylene.
本研究通过镍模板一锅缩合法合成了 2-t-丁基-4-芳基亚氨基-2,3-二氢吖啶基镍二溴化物，并对其中一个代表性络合物进行了单晶 X 射线衍射表征，发现镍周围存在扭曲的四面体几何形状。当用改性甲基铝氧烷（MMAO）激活时，所有镍络合物都表现出很高的活性（高达 1.91 × 106 g mol-1 (Ni) h-1），可实现乙烯的主要三聚化。然而，当用二氯化铝（EtAlCl2）激活时，标题络合物在乙烯的选择性二聚化方面表现出良好的活性（高达 1.05 × 106 g mol-1 (Ni) h-1）。与类似的镍络合物相比，以叔丁基为取代基的镍络合物具有更高的活性，尤其是在镍络合物对乙烯进行三聚的罕见情况下。
{"title":"On-Purpose Oligomerization by 2-t-Butyl-4-arylimino-2,3-dihydroacridylnickel(II) Bromides","authors":"Song Zou, Zheng Wang, Yizhou Wang, Yanping Ma, Yang Sun, Wen-Hua Sun","doi":"10.3390/catal14060342","DOIUrl":"https://doi.org/10.3390/catal14060342","url":null,"abstract":"In this study, 2-t-butyl-4-arylimino-2,3-dihydroacridylnickel dibromides were synthesized by nickel-template one-pot condensation, and well characterized along with the single-crystal X-ray diffraction to one representative complex, revealing a distorted tetrahedral geometry around nickel. When activated with modified methylaluminoxane (MMAO), all nickel complexes exhibited high activities (up to 1.91 × 106 g mol−1 (Ni) h−1) toward major trimerization of ethylene. When activated with ethylaluminum dichloride (EtAlCl2), however, the title complexes performed good activities (up to 1.05 × 106 g mol−1 (Ni) h−1) for selective dimerization of ethylene. In comparison to analogous nickel complexes, higher activities were achieved with the substituent of t-butyl group, especially in the rare case of nickel complexes performing trimerization of ethylene.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141102053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
There are plenty of challenges related to the current energy situation [...]
当前的能源形势面临诸多挑战 [...]
{"title":"Editorial: Biomass Derived Heterogeneous and Homogeneous Catalysts, 2nd Edition","authors":"José María Encinar Martín, S. Nogales-Delgado","doi":"10.3390/catal14060339","DOIUrl":"https://doi.org/10.3390/catal14060339","url":null,"abstract":"There are plenty of challenges related to the current energy situation [...]","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141105224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Excessive emissions of carbon dioxide have led to the greenhouse effect and global warming. Reducing carbon dioxide into high-value-added chemicals through solar energy is a promising approach. Herein, a g-C3N4/TiO2 heterojunction photocatalyst with efficient electron transfer is designed for photocatalytic CO2 reduction. The CH4 (18.32 µmol·h−1·g−1) and CO (25.35 µmol·h−1·g−1) evolution rates of g-C3N4/TiO2 are higher than those of g-C3N4 and TiO2. The enhanced photocatalytic CO2 reduction performance is attributed to the efficient charge carrier transfer in the g-C3N4/TiO2 heterojunction. The electron transfer route was verified by in situ irradiated X-ray photoelectron spectroscopy (XPS). The photocatalytic CO2 reduction mechanism on g-C3N4/TiO2 was investigated by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). This work provides a strategy for designing a polymer/metallic oxide heterojunction with efficient electron transfer for enhanced photocatalytic CO2 reduction.
二氧化碳的过度排放导致了温室效应和全球变暖。通过太阳能将二氧化碳还原成高附加值化学品是一种前景广阔的方法。本文设计了一种具有高效电子传递功能的 g-C3N4/TiO2 异质结光催化剂，用于光催化还原二氧化碳。g-C3N4/TiO2 的 CH4（18.32 µmol-h-1-g-1）和 CO（25.35 µmol-h-1-g-1）演化率高于 g-C3N4 和 TiO2。光催化还原 CO2 性能的提高归功于 g-C3N4/TiO2 异质结中高效的电荷载流子转移。原位辐照 X 射线光电子能谱（XPS）验证了电子转移途径。通过原位漫反射红外傅里叶变换光谱（DRIFTS）研究了 g-C3N4/TiO2 光催化还原 CO2 的机理。这项研究为设计具有高效电子传递功能的聚合物/金属氧化物异质结以增强光催化还原 CO2 提供了一种策略。
{"title":"Efficient Electron Transfer in g-C3N4/TiO2 Heterojunction for Enhanced Photocatalytic CO2 Reduction","authors":"Peng Jiang, Yang Yu, Kun Wang, Wenrui Liu","doi":"10.3390/catal14060335","DOIUrl":"https://doi.org/10.3390/catal14060335","url":null,"abstract":"Excessive emissions of carbon dioxide have led to the greenhouse effect and global warming. Reducing carbon dioxide into high-value-added chemicals through solar energy is a promising approach. Herein, a g-C3N4/TiO2 heterojunction photocatalyst with efficient electron transfer is designed for photocatalytic CO2 reduction. The CH4 (18.32 µmol·h−1·g−1) and CO (25.35 µmol·h−1·g−1) evolution rates of g-C3N4/TiO2 are higher than those of g-C3N4 and TiO2. The enhanced photocatalytic CO2 reduction performance is attributed to the efficient charge carrier transfer in the g-C3N4/TiO2 heterojunction. The electron transfer route was verified by in situ irradiated X-ray photoelectron spectroscopy (XPS). The photocatalytic CO2 reduction mechanism on g-C3N4/TiO2 was investigated by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). This work provides a strategy for designing a polymer/metallic oxide heterojunction with efficient electron transfer for enhanced photocatalytic CO2 reduction.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141109438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jianxiong Du, Wanhe Wang, Jinbiao Liu, Nianhua Luo
A novel protocol facilitated by Na2SO3 that enhances the efficiency of palladium-catalyzed Heck coupling and the homo-coupling reactions of arylhydrazines. This innovative method enables the effective construction of a diverse array of cinnamate derivatives and biphenyl compounds. Notably, these transformative reactions proceed smoothly at room temperature, leveraging the activation of C-N bonds. This technique not only streamlines the synthesis process but also expands our understanding and expertise in the realm of coupling reactions.
{"title":"Na2SO3-Promoted Heck Coupling and Homo-Coupling of Arylhydrazines at Room Temperature","authors":"Jianxiong Du, Wanhe Wang, Jinbiao Liu, Nianhua Luo","doi":"10.3390/catal14060338","DOIUrl":"https://doi.org/10.3390/catal14060338","url":null,"abstract":"A novel protocol facilitated by Na2SO3 that enhances the efficiency of palladium-catalyzed Heck coupling and the homo-coupling reactions of arylhydrazines. This innovative method enables the effective construction of a diverse array of cinnamate derivatives and biphenyl compounds. Notably, these transformative reactions proceed smoothly at room temperature, leveraging the activation of C-N bonds. This technique not only streamlines the synthesis process but also expands our understanding and expertise in the realm of coupling reactions.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141110320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sajid Ali, Sidra, Tanveer Asghar, Muhammad Ishtiaq Jan, Muhammad Waqas, Tahir Ali, Riaz Ullah, Ahmed Bari
Zinc oxide nanoparticles (ZnO NPs) are becoming an innovative agent in biological and environmental applications due to its unique characteristics, biocompatibility, low cost and toxicity. In this study, the composite ZnO NPs using Rhododendron arboreum (R. arboreum) stem bark were synthesized and characterized for UV–visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The biomedical assessment of the synthesized nanoparticles showed zones of inhibition of 23 ± 0.09, 18 ± 0.1 and 16 ± 0.05 mm, against the Klebsiella pneumoniae (K. pneumoniae), Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) strains, respectively. Likewise, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against K. pneumoniae, S. aureus, and E. coli were found to be 34 ± 0.21 and 72.71 ± 0.47, 47 ± 0.11 and 94.86 ± 0.84 and 94 ± 0.18 and 185.43 ± 0.16 µg/mL, respectively. The biosynthesized ZnO NPs resulted in significant eradication of the outer and inner membranes of the tested bacterial cells. In addition, the environmental application of the synthesized ZnO NPs also showed time-dependent photocatalytic degradation activity and revealed 65% methyl orange dye degradation with an irradiation period of 6 h. The findings of this study suggest the suitability of the novel R. arboreum stem bark-based ZnO NPs as an effective ameliorant against bactericidal activities and photocatalytic potential for the removal of potentially toxic substances from water.
{"title":"Green Synthesis of Novel Rhododendron arboreum-Based Zinc Oxide Nanoparticles for Enhanced Antimicrobial and Photocatalytic Degradation Activities","authors":"Sajid Ali, Sidra, Tanveer Asghar, Muhammad Ishtiaq Jan, Muhammad Waqas, Tahir Ali, Riaz Ullah, Ahmed Bari","doi":"10.3390/catal14060337","DOIUrl":"https://doi.org/10.3390/catal14060337","url":null,"abstract":"Zinc oxide nanoparticles (ZnO NPs) are becoming an innovative agent in biological and environmental applications due to its unique characteristics, biocompatibility, low cost and toxicity. In this study, the composite ZnO NPs using Rhododendron arboreum (R. arboreum) stem bark were synthesized and characterized for UV–visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The biomedical assessment of the synthesized nanoparticles showed zones of inhibition of 23 ± 0.09, 18 ± 0.1 and 16 ± 0.05 mm, against the Klebsiella pneumoniae (K. pneumoniae), Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) strains, respectively. Likewise, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against K. pneumoniae, S. aureus, and E. coli were found to be 34 ± 0.21 and 72.71 ± 0.47, 47 ± 0.11 and 94.86 ± 0.84 and 94 ± 0.18 and 185.43 ± 0.16 µg/mL, respectively. The biosynthesized ZnO NPs resulted in significant eradication of the outer and inner membranes of the tested bacterial cells. In addition, the environmental application of the synthesized ZnO NPs also showed time-dependent photocatalytic degradation activity and revealed 65% methyl orange dye degradation with an irradiation period of 6 h. The findings of this study suggest the suitability of the novel R. arboreum stem bark-based ZnO NPs as an effective ameliorant against bactericidal activities and photocatalytic potential for the removal of potentially toxic substances from water.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141109258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Farid Hajareh Haghighi, Roya Binaymotlagh, C. Palocci, L. Chronopoulou
Biodiesel is a mixture of fatty acid alkyl esters (FAAEs) mainly produced via transesterification reactions among triglycerides and short-chain alcohols catalyzed by chemical catalysts (e.g., KOH, NaOH). Lipase-assisted enzymatic transesterification has been proposed to overcome the drawbacks of chemical synthesis, such as high energy consumption, expensive separation of the catalyst from the reaction mixture and production of large amounts of wastewater during product separation and purification. However, one of the main drawbacks of this process is the enzyme cost. In recent years, nano-immobilized lipases have received extensive attention in the design of robust industrial biocatalysts for biodiesel production. To improve lipase catalytic efficiency, magnetic nanoparticles (MNPs) have attracted growing interest as versatile lipase carriers, owing to their unique properties, such as high surface-to-volume ratio and high enzyme loading capacity, low cost and inertness against chemical and microbial degradation, biocompatibility and eco-friendliness, standard synthetic methods for large-scale production and, most importantly, magnetic properties, which provide the possibility for the immobilized lipase to be easily separated at the end of the process by applying an external magnetic field. For the preparation of such effective magnetic nano-supports, various surface functionalization approaches have been developed to immobilize a broad range of industrially important lipases. Immobilization generally improves lipase chemical-thermal stability in a wide pH and temperature range and may also modify its catalytic performance. Additionally, different lipases can be co-immobilized onto the same nano-carrier, which is a highly effective strategy to enhance biodiesel yield, specifically for those feedstocks containing heterogeneous free fatty acids (FFAs). This review will present an update on the use of magnetic iron oxide nanostructures (MNPs) for lipase immobilization to catalyze transesterification reactions for biodiesel production. The following aspects will be covered: (1) common organic modifiers for magnetic nanoparticle support and (2) recent studies on modified MNPs-lipase catalysts for biodiesel production. Aspects concerning immobilization procedures and surface functionalization of the nano-supports will be highlighted. Additionally, the main features that characterize these nano-biocatalysts, such as enzymatic activity, reusability, resistance to heat and pH, will be discussed. Perspectives and key considerations for optimizing biodiesel production in terms of sustainability are also provided for future studies.
{"title":"Magnetic Iron Oxide Nanomaterials for Lipase Immobilization: Promising Industrial Catalysts for Biodiesel Production","authors":"Farid Hajareh Haghighi, Roya Binaymotlagh, C. Palocci, L. Chronopoulou","doi":"10.3390/catal14060336","DOIUrl":"https://doi.org/10.3390/catal14060336","url":null,"abstract":"Biodiesel is a mixture of fatty acid alkyl esters (FAAEs) mainly produced via transesterification reactions among triglycerides and short-chain alcohols catalyzed by chemical catalysts (e.g., KOH, NaOH). Lipase-assisted enzymatic transesterification has been proposed to overcome the drawbacks of chemical synthesis, such as high energy consumption, expensive separation of the catalyst from the reaction mixture and production of large amounts of wastewater during product separation and purification. However, one of the main drawbacks of this process is the enzyme cost. In recent years, nano-immobilized lipases have received extensive attention in the design of robust industrial biocatalysts for biodiesel production. To improve lipase catalytic efficiency, magnetic nanoparticles (MNPs) have attracted growing interest as versatile lipase carriers, owing to their unique properties, such as high surface-to-volume ratio and high enzyme loading capacity, low cost and inertness against chemical and microbial degradation, biocompatibility and eco-friendliness, standard synthetic methods for large-scale production and, most importantly, magnetic properties, which provide the possibility for the immobilized lipase to be easily separated at the end of the process by applying an external magnetic field. For the preparation of such effective magnetic nano-supports, various surface functionalization approaches have been developed to immobilize a broad range of industrially important lipases. Immobilization generally improves lipase chemical-thermal stability in a wide pH and temperature range and may also modify its catalytic performance. Additionally, different lipases can be co-immobilized onto the same nano-carrier, which is a highly effective strategy to enhance biodiesel yield, specifically for those feedstocks containing heterogeneous free fatty acids (FFAs). This review will present an update on the use of magnetic iron oxide nanostructures (MNPs) for lipase immobilization to catalyze transesterification reactions for biodiesel production. The following aspects will be covered: (1) common organic modifiers for magnetic nanoparticle support and (2) recent studies on modified MNPs-lipase catalysts for biodiesel production. Aspects concerning immobilization procedures and surface functionalization of the nano-supports will be highlighted. Additionally, the main features that characterize these nano-biocatalysts, such as enzymatic activity, reusability, resistance to heat and pH, will be discussed. Perspectives and key considerations for optimizing biodiesel production in terms of sustainability are also provided for future studies.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141112256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, graphene quantum dots (GQDs) have been incorporated into the g-C3N4/ZIF-67 heterojunction system as a photosensitizer to enhance photocatalytic conversion of CO2-to-CO. The GQDs are deposited onto the surface of g-C3N4/ZIF-67 using a simple water bath procedure. As expected, GQDs/g-C3N4/ZIF-67 presents outstanding performance in CO2 photoreduction. Among the GQDs/g-C3N4/ZIF-67 ternary photocatalysts, 7 GQDs-CN/ZIF-67 exhibits the best photocatalytic CO2 reduction ability with a CO yield of 51.71 μmol g−1, which is 5.05 and 1.87 times more than pristine g-C3N4 (10.24 μmol g−1) and g-C3N4/ZIF-67 (27.65 μmol g−1), respectively. This result shows that upon combination of GQDs with ZIF-67/g-C3N4, GQDs can be used as photosensitizers to improve the optical absorption capacity of the photocatalyst. Furthermore, GQDs serve as electron channels, facilitating the transport of photo-induced electrons from ZIF-67 to g-C3N4, which promotes photogenerated carrier separation efficiency. This study innovatively adds GQDs to the heterojunction and applies the prepared ternary composite to the CO2 photoreduction, which inspires a novel direction for the design of non-noble metal photocatalysts.
{"title":"Construction of a Novel Ternary GQDs/g-C3N4/ZIF-67 Photocatalyst for Enhanced Photocatalytic Carbon Dioxide Reduction","authors":"Zhiyuan Zhao, Jingjing Wang, Congnian Xu, Zhao Du, Rongrong Yu, Yongqi Zhao, Jiayi Han, Jingtao Zuo, Zhonglu Guo, Chengchun Tang, Yi Fang","doi":"10.3390/catal14060334","DOIUrl":"https://doi.org/10.3390/catal14060334","url":null,"abstract":"In this study, graphene quantum dots (GQDs) have been incorporated into the g-C3N4/ZIF-67 heterojunction system as a photosensitizer to enhance photocatalytic conversion of CO2-to-CO. The GQDs are deposited onto the surface of g-C3N4/ZIF-67 using a simple water bath procedure. As expected, GQDs/g-C3N4/ZIF-67 presents outstanding performance in CO2 photoreduction. Among the GQDs/g-C3N4/ZIF-67 ternary photocatalysts, 7 GQDs-CN/ZIF-67 exhibits the best photocatalytic CO2 reduction ability with a CO yield of 51.71 μmol g−1, which is 5.05 and 1.87 times more than pristine g-C3N4 (10.24 μmol g−1) and g-C3N4/ZIF-67 (27.65 μmol g−1), respectively. This result shows that upon combination of GQDs with ZIF-67/g-C3N4, GQDs can be used as photosensitizers to improve the optical absorption capacity of the photocatalyst. Furthermore, GQDs serve as electron channels, facilitating the transport of photo-induced electrons from ZIF-67 to g-C3N4, which promotes photogenerated carrier separation efficiency. This study innovatively adds GQDs to the heterojunction and applies the prepared ternary composite to the CO2 photoreduction, which inspires a novel direction for the design of non-noble metal photocatalysts.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141116740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ilias Papailias, N. Todorova, T. Giannakopoulou, Niki Plakantonaki, Michail Vagenas, Panagiotis Dallas, G. Anyfantis, Ioannis Arabatzis, C. Trapalis
In the last few years, increasing interest from researchers and companies has been shown in the development of photocatalytic coatings for air purification and self-cleaning applications. In order to maintain the photocatalyst’s concentration as low as possible, highly active materials and/or combinations of them are required. In this work, novel photocatalytic formulations containing g-C3N4/TiO2 composites were prepared and deposited in the form of coatings on a-block substrates. The obtained photocatalytic surfaces were tested for NOx and acetaldehyde removal from model air. It was found that the addition of only 0.5 wt% g-C3N4 towards TiO2 content results in over 50% increase in the photocatalytic activity under visible light irradiation in comparison to pure TiO2 coating, while the activity under UV light was not affected. The result was related to the creation of a g-C3N4/TiO2 heterojunction that improves the light absorption and the separation of photogenerated electron-hole pairs, as well as to the inhibition of TiO2 particles’ agglomeration due to the presence of g-C3N4 sheets.
{"title":"Enhancing the Visible Light Photocatalytic Activity of TiO2-Based Coatings by the Addition of Exfoliated g-C3N4","authors":"Ilias Papailias, N. Todorova, T. Giannakopoulou, Niki Plakantonaki, Michail Vagenas, Panagiotis Dallas, G. Anyfantis, Ioannis Arabatzis, C. Trapalis","doi":"10.3390/catal14050333","DOIUrl":"https://doi.org/10.3390/catal14050333","url":null,"abstract":"In the last few years, increasing interest from researchers and companies has been shown in the development of photocatalytic coatings for air purification and self-cleaning applications. In order to maintain the photocatalyst’s concentration as low as possible, highly active materials and/or combinations of them are required. In this work, novel photocatalytic formulations containing g-C3N4/TiO2 composites were prepared and deposited in the form of coatings on a-block substrates. The obtained photocatalytic surfaces were tested for NOx and acetaldehyde removal from model air. It was found that the addition of only 0.5 wt% g-C3N4 towards TiO2 content results in over 50% increase in the photocatalytic activity under visible light irradiation in comparison to pure TiO2 coating, while the activity under UV light was not affected. The result was related to the creation of a g-C3N4/TiO2 heterojunction that improves the light absorption and the separation of photogenerated electron-hole pairs, as well as to the inhibition of TiO2 particles’ agglomeration due to the presence of g-C3N4 sheets.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141120474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The catalytic isomerization of glucose to fructose plays a pivotal role in the application of biomass as a feedstock for chemicals. Herein, we propose a facile solid-state-grinding strategy to construct ZrO2/MgO mixed oxides, which offered an excellent fructose yield of over 34.55% and a high selectivity of 80.52% (80 °C, 2 h). The co-mingling of amphiphilic ZrO2 with MgO improved the unfavorable moderate/strongly basic site distribution on MgO, which can prohibit the side reactions during the reaction and enhance the fructose selectivity. Based on the catalyst characterizations, MgO was deposited on the ZrO2 surface by plugging the pores, and the addition of ZrO2 lessened the quantity of strongly basic sites of MgO. Additionally, the presence of ZrO2 largely enhanced the catalyst stability in comparison with pure MgO by recycling experiments.
{"title":"Glucose Isomerization to Fructose Catalyzed by MgZr Mixed Oxides in Aqueous Solution","authors":"Xiongxiong Zuo, Xing Tang","doi":"10.3390/catal14050332","DOIUrl":"https://doi.org/10.3390/catal14050332","url":null,"abstract":"The catalytic isomerization of glucose to fructose plays a pivotal role in the application of biomass as a feedstock for chemicals. Herein, we propose a facile solid-state-grinding strategy to construct ZrO2/MgO mixed oxides, which offered an excellent fructose yield of over 34.55% and a high selectivity of 80.52% (80 °C, 2 h). The co-mingling of amphiphilic ZrO2 with MgO improved the unfavorable moderate/strongly basic site distribution on MgO, which can prohibit the side reactions during the reaction and enhance the fructose selectivity. Based on the catalyst characterizations, MgO was deposited on the ZrO2 surface by plugging the pores, and the addition of ZrO2 lessened the quantity of strongly basic sites of MgO. Additionally, the presence of ZrO2 largely enhanced the catalyst stability in comparison with pure MgO by recycling experiments.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141125326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Heterogeneous thermal-catalytic CO2 hydrogenation to alcohols using renewable energy is a highly attractive approach for recycling greenhouse gases into high-value chemicals and fuels, thereby reducing the dependence on fossil fuels, while simultaneously mitigating the CO2 emission and environmental problems. Currently, great advances have been made on the heterogeneous catalysts, but an in-depth and more comprehensive understanding to further promote this reaction process is still lacking. Herein, we highlight the thermodynamic and kinetic analysis of CO2 hydrogenation reaction firstly. Then, various reaction pathways for CO2 hydrogenation to methanol and higher alcohols (C2+ alcohols) have been discussed in detail, respectively, by combining the experimental studies and density functional theory calculations. On this basis, the key factors influencing the reaction performance, such as metal dispersion, support modification, promoter addition and their structural optimization, are summarized on the metal-based and metal-oxide-based catalysts. In addition, the catalytic performance of CO2 hydrogenation to alcohols and the relationship between structure and properties are mainly summarized and analyzed in the past five years. To conclude, the current challenges and potential strategies in catalyst design, structural characterization and reaction mechanisms are presented for CO2 hydrogenation to alcohols.
利用可再生能源进行异相热催化二氧化碳加氢制取醇类是一种极具吸引力的方法，可将温室气体回收利用为高价值的化学品和燃料，从而减少对化石燃料的依赖，同时缓解二氧化碳排放和环境问题。目前，在异相催化剂方面已经取得了很大进展，但仍缺乏对进一步促进该反应过程的更深入、更全面的了解。在此，我们首先重点介绍二氧化碳加氢反应的热力学和动力学分析。然后，结合实验研究和密度泛函理论计算，分别详细讨论了 CO2 加氢制甲醇和高级醇（C2+ 醇）的各种反应途径。在此基础上，总结了影响金属基和金属氧化物基催化剂反应性能的关键因素，如金属分散、载体改性、促进剂添加及其结构优化等。此外，还主要总结和分析了近五年来 CO2 加氢制醇的催化性能以及结构与性能之间的关系。最后，介绍了目前 CO2 加氢制醇在催化剂设计、结构表征和反应机理方面面临的挑战和可能的策略。
{"title":"Review of Mechanism Investigations and Catalyst Developments for CO2 Hydrogenation to Alcohols","authors":"Guoqing Cui, Yingjie Lou, Mingxia Zhou, Yuming Li, Guiyuan Jiang, Chunming Xu","doi":"10.3390/catal14040232","DOIUrl":"https://doi.org/10.3390/catal14040232","url":null,"abstract":"Heterogeneous thermal-catalytic CO2 hydrogenation to alcohols using renewable energy is a highly attractive approach for recycling greenhouse gases into high-value chemicals and fuels, thereby reducing the dependence on fossil fuels, while simultaneously mitigating the CO2 emission and environmental problems. Currently, great advances have been made on the heterogeneous catalysts, but an in-depth and more comprehensive understanding to further promote this reaction process is still lacking. Herein, we highlight the thermodynamic and kinetic analysis of CO2 hydrogenation reaction firstly. Then, various reaction pathways for CO2 hydrogenation to methanol and higher alcohols (C2+ alcohols) have been discussed in detail, respectively, by combining the experimental studies and density functional theory calculations. On this basis, the key factors influencing the reaction performance, such as metal dispersion, support modification, promoter addition and their structural optimization, are summarized on the metal-based and metal-oxide-based catalysts. In addition, the catalytic performance of CO2 hydrogenation to alcohols and the relationship between structure and properties are mainly summarized and analyzed in the past five years. To conclude, the current challenges and potential strategies in catalyst design, structural characterization and reaction mechanisms are presented for CO2 hydrogenation to alcohols.","PeriodicalId":9794,"journal":{"name":"Catalysts","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140361161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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