The process of light-induced C-H oxygenation is of high interest as it can be used for the construction of oxygenated compounds. Herein, we report a mild and general method for the efficient synthesis of aromatic ketones following the process of metal-free C-H oxygenation. With air as the oxidant, high functional tolerance was demonstrated, and the desired ketones were obtained in moderate to excellent yields at room temperature (25 oC). Mechanistic studies suggested that the oxidative transformation potentially occurred via an electron transfer pathway.
{"title":"Visible-Light-Induced Formation of Aromatic Ketones: A Metal-Free C−H Oxygenation Process in Air under Room Temperature","authors":"Pan Xie, Dongdong Du, C. Xue, Sanshan Shi","doi":"10.21926/cr.2202014","DOIUrl":"https://doi.org/10.21926/cr.2202014","url":null,"abstract":"The process of light-induced C-H oxygenation is of high interest as it can be used for the construction of oxygenated compounds. Herein, we report a mild and general method for the efficient synthesis of aromatic ketones following the process of metal-free C-H oxygenation. With air as the oxidant, high functional tolerance was demonstrated, and the desired ketones were obtained in moderate to excellent yields at room temperature (25 oC). Mechanistic studies suggested that the oxidative transformation potentially occurred via an electron transfer pathway.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125632934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new chiral cyclopalladated ferrocenyl imine catalyst (called 4a2) was designed and synthesized, and its self-assembly catalytic polymeric brush supported on silicon (denoted as Si@PB4a2) was also fabricated by surface-initiated atom transfer radical polymerization (ATRP) and characterized. The catalytic properties of monomer 4a2 in homogeneous and Si@PB4a2 in heterogeneous in Heck and Suzuki cross-coupling were investigated, respectively. They exhibited higher catalytic activity in Heck, and Suzuki coupling reactions in homogeneous and heterogeneous using water as the solvent, and the catalytic activity of Si@PB4a2 with a turn of number (TON,11933 molproduct/molcat) in heterogeneous was 200 times more than that of 4a2 in homogeneous due to the ordered arrangement of the catalyst supported on silicon. Si@PB4a2 had high recyclability, i.e., at least eight runs and six runs, in Suzuki and Heck coupling reactions, respectively.
{"title":"A New Chiral Cyclopalladated Ferrocenylimine Self-assembly Polymeric Film supported on Silicon for Heck and Suzuki-coupling Reactions","authors":"Mingyu Wang, Jie Liu, Jinpeng Li, Tiesheng Li","doi":"10.21926/cr.2202010","DOIUrl":"https://doi.org/10.21926/cr.2202010","url":null,"abstract":"A new chiral cyclopalladated ferrocenyl imine catalyst (called 4a2) was designed and synthesized, and its self-assembly catalytic polymeric brush supported on silicon (denoted as Si@PB4a2) was also fabricated by surface-initiated atom transfer radical polymerization (ATRP) and characterized. The catalytic properties of monomer 4a2 in homogeneous and Si@PB4a2 in heterogeneous in Heck and Suzuki cross-coupling were investigated, respectively. They exhibited higher catalytic activity in Heck, and Suzuki coupling reactions in homogeneous and heterogeneous using water as the solvent, and the catalytic activity of Si@PB4a2 with a turn of number (TON,11933 molproduct/molcat) in heterogeneous was 200 times more than that of 4a2 in homogeneous due to the ordered arrangement of the catalyst supported on silicon. Si@PB4a2 had high recyclability, i.e., at least eight runs and six runs, in Suzuki and Heck coupling reactions, respectively.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116257155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Enzymes are extensively used in biotechnological processes in several areas of industry. They are sustainable and safe, and their specificity is another characteristic that improves the performance in the process. Among enzymes, lipase is relevant due to the ability to play different roles in the industry and the possibility of collecting them from microbial sources that are found in industrial residues. This can reduce the costs of enzyme production. In relation to that, lipase immobilization is an interesting process that allows the enzymes to be reused and improves enzyme robustness. Among them, the cross-linked enzyme aggregates (CLEAs) methodology is attractive due to its simplicity, low cost (given the absence of support), and greater interaction with the substrate. Thus, in this review, we discussed the potential of lipase. We reviewed the traditional and new sources of obtaining lipases, along with the ways of improving production, activity, and application in the industry.
{"title":"Lipases: Sources of Acquisition, Ways of Production, and Recent Applications","authors":"M. Santos, D. Hirata, Joelise A. F. Angelotti","doi":"10.21926/cr.2202013","DOIUrl":"https://doi.org/10.21926/cr.2202013","url":null,"abstract":"Enzymes are extensively used in biotechnological processes in several areas of industry. They are sustainable and safe, and their specificity is another characteristic that improves the performance in the process. Among enzymes, lipase is relevant due to the ability to play different roles in the industry and the possibility of collecting them from microbial sources that are found in industrial residues. This can reduce the costs of enzyme production. In relation to that, lipase immobilization is an interesting process that allows the enzymes to be reused and improves enzyme robustness. Among them, the cross-linked enzyme aggregates (CLEAs) methodology is attractive due to its simplicity, low cost (given the absence of support), and greater interaction with the substrate. Thus, in this review, we discussed the potential of lipase. We reviewed the traditional and new sources of obtaining lipases, along with the ways of improving production, activity, and application in the industry.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132725540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The use of Pd-Cu bimetallic catalysts in the reduction of aqueous nitrate ions by hydrogen was studied. The catalysts were supported on multi-walled carbon nanotubes (MWCNTs), activated carbon (AC), and Titania, and the influence of the support on the nitrate reduction activity in water was then investigated. The catalysts were characterized before and after use by FT-IR, XRD, SEM, EDX, and Laser Granulometry. It was found that the surface characteristics of the support have an influence on the catalyst activity, with Pd-Cu supported on MWCNT displaying the highest reduction efficiency.
{"title":"Pd-Cu Bimetallic Based Catalysts for Nitrate Remediation in Water: Synthesis, Characterization, and the Influence of Supports","authors":"Mouhamad Rachini","doi":"10.21926/cr.2202011","DOIUrl":"https://doi.org/10.21926/cr.2202011","url":null,"abstract":"The use of Pd-Cu bimetallic catalysts in the reduction of aqueous nitrate ions by hydrogen was studied. The catalysts were supported on multi-walled carbon nanotubes (MWCNTs), activated carbon (AC), and Titania, and the influence of the support on the nitrate reduction activity in water was then investigated. The catalysts were characterized before and after use by FT-IR, XRD, SEM, EDX, and Laser Granulometry. It was found that the surface characteristics of the support have an influence on the catalyst activity, with Pd-Cu supported on MWCNT displaying the highest reduction efficiency.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129992348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rui Wang, D. Lin, Minghuan Gao, Linna Guo, Tiesheng Li, Minghua Liu
A series of novel Bi2MoO6/Ag/Ag2CrO4 heterostructure photocatalysts (denoted as BA-X, X = 1, 3, 5, 10) were synthesized using a coprecipitation method. These photocatalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-vis spectroscopy, and X-ray photoelectron spectroscopy (XPS) and their photocatalytic properties were investigated. Compared with pure Bi2MoO6 or Ag2CrO4, BA-5 exhibited a higher photocatalytic property and broader light absorption. In addition, the surface plasmon resonance (SPR) effect of Ag enhanced the separation of photogenerated carriers. BA-5 could be recycled at least five times, and XRD and SEM of BA-5 during the cycles were measured, revealing that the crystal structure and morphology were changed with the increase in the number of cycles. The trapping agent experiments indicated that the holes had a more decisive impact on the degradation of RhB; the degradation mechanism was proposed as Type I.
采用共沉淀法合成了一系列新型Bi2MoO6/Ag/Ag2CrO4异质结构光催化剂(记为BA-X, X = 1,3,5,10)。采用扫描电镜(SEM)、x射线衍射(XRD)、紫外可见光谱(UV-vis)和x射线光电子能谱(XPS)对催化剂进行了表征，并对其光催化性能进行了研究。与纯Bi2MoO6或Ag2CrO4相比，BA-5具有更高的光催化性能和更广泛的光吸收。此外，银的表面等离子体共振(SPR)效应增强了光生载流子的分离。BA-5至少可循环5次，对循环过程中BA-5的XRD和SEM进行了测量，发现随着循环次数的增加，BA-5的晶体结构和形貌发生了变化。捕集剂实验表明，孔洞对RhB的降解具有决定性的影响;降解机制为ⅰ型。
{"title":"Preparation of a Novel Bi2MoO6/Ag/Ag2CrO4 Catalyst with Promoted Visible Light Photodegradation of RhB Dye","authors":"Rui Wang, D. Lin, Minghuan Gao, Linna Guo, Tiesheng Li, Minghua Liu","doi":"10.21926/cr.2202008","DOIUrl":"https://doi.org/10.21926/cr.2202008","url":null,"abstract":"A series of novel Bi2MoO6/Ag/Ag2CrO4 heterostructure photocatalysts (denoted as BA-X, X = 1, 3, 5, 10) were synthesized using a coprecipitation method. These photocatalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-vis spectroscopy, and X-ray photoelectron spectroscopy (XPS) and their photocatalytic properties were investigated. Compared with pure Bi2MoO6 or Ag2CrO4, BA-5 exhibited a higher photocatalytic property and broader light absorption. In addition, the surface plasmon resonance (SPR) effect of Ag enhanced the separation of photogenerated carriers. BA-5 could be recycled at least five times, and XRD and SEM of BA-5 during the cycles were measured, revealing that the crystal structure and morphology were changed with the increase in the number of cycles. The trapping agent experiments indicated that the holes had a more decisive impact on the degradation of RhB; the degradation mechanism was proposed as Type I.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130759575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Galarneau, Lucie Desmurs, C. Vaulot, H. Nouali, B. Lebeau, T. Daou, V. Hulea, C. Cammarano, I. Batonneau-Gener, A. Sachse
It is important to elucidate the role of the surface areas and pore volumes of hierarchical zeolites to understand their behavior as catalysts. Micro-and mesopore surface areas and volumes of the hierarchical MFI (Mobil Five zeolites) were assessed following several methods: (i) N2 adsorption at 77 K using classical and corrected t-plot analyses methods, (ii) pre-adsorption of n-nonane was followed by the study of the N2 adsorption at 77 K, and (iii) non-local-density functional theory (NLDFT) analysis using either the N2 adsorption method at 77 K or the Ar adsorption method at 87 K. In order to assess the viability of each method, a set of hierarchical MFI-type zeolites was prepared by different approaches: alkaline treatment (desilication), synthesis in clear solution (nanocrystals), synthesis in the presence of bifunctional organic surfactant (nanosheets), and micelle-templating assisted alkaline treatment. NLDFT methods could not be used to accurately determine the micro-and mesopore surface areas, as larger surface areas compared to those obtained using the BET equation were obtained. This overestimation is even more pronounced with Ar at 87 K. Results from the classical t-plot analysis performed under conditions of N2 adsorption at 77 K for mechanical mixtures of MFI and MCM-41 revealed the underestimation of the micropore volumes and the overestimation of the mesopore surface areas. Corrections were provided for t-plot analysis. The results obtained using the corrected t-plot method were in good agreement with the results obtained using the NLDFT method in the presence of Ar at 87 K during the calculation of the micro-and mesopore volumes of hierarchical MFI-type zeolites. Micropore and mesopore surface areas calculated by the corrected t-plot method were in good agreement with those calculated using the n-nonane pre-adsorption method for the hierarchical MFI-type zeolites characterized by the presence of large zeolite domains. The NLDFT method, in the presence of Ar, can be used to assess the micro-and mesopore volumes of the hierarchical zeolites at 87 K. However, it cannot be used to determine the surface areas. The corrected t-plot method can be used to efficiently calculate both the volumes and surface areas.
{"title":"Hierarchical MFI Zeolite Catalysts: How to Determine Their Textural Properties?-A Comparative Study","authors":"A. Galarneau, Lucie Desmurs, C. Vaulot, H. Nouali, B. Lebeau, T. Daou, V. Hulea, C. Cammarano, I. Batonneau-Gener, A. Sachse","doi":"10.21926/cr.2202009","DOIUrl":"https://doi.org/10.21926/cr.2202009","url":null,"abstract":"It is important to elucidate the role of the surface areas and pore volumes of hierarchical zeolites to understand their behavior as catalysts. Micro-and mesopore surface areas and volumes of the hierarchical MFI (Mobil Five zeolites) were assessed following several methods: (i) N2 adsorption at 77 K using classical and corrected t-plot analyses methods, (ii) pre-adsorption of n-nonane was followed by the study of the N2 adsorption at 77 K, and (iii) non-local-density functional theory (NLDFT) analysis using either the N2 adsorption method at 77 K or the Ar adsorption method at 87 K. In order to assess the viability of each method, a set of hierarchical MFI-type zeolites was prepared by different approaches: alkaline treatment (desilication), synthesis in clear solution (nanocrystals), synthesis in the presence of bifunctional organic surfactant (nanosheets), and micelle-templating assisted alkaline treatment. NLDFT methods could not be used to accurately determine the micro-and mesopore surface areas, as larger surface areas compared to those obtained using the BET equation were obtained. This overestimation is even more pronounced with Ar at 87 K. Results from the classical t-plot analysis performed under conditions of N2 adsorption at 77 K for mechanical mixtures of MFI and MCM-41 revealed the underestimation of the micropore volumes and the overestimation of the mesopore surface areas. Corrections were provided for t-plot analysis. The results obtained using the corrected t-plot method were in good agreement with the results obtained using the NLDFT method in the presence of Ar at 87 K during the calculation of the micro-and mesopore volumes of hierarchical MFI-type zeolites. Micropore and mesopore surface areas calculated by the corrected t-plot method were in good agreement with those calculated using the n-nonane pre-adsorption method for the hierarchical MFI-type zeolites characterized by the presence of large zeolite domains. The NLDFT method, in the presence of Ar, can be used to assess the micro-and mesopore volumes of the hierarchical zeolites at 87 K. However, it cannot be used to determine the surface areas. The corrected t-plot method can be used to efficiently calculate both the volumes and surface areas.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130081330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thibaut Triquet, C. Tendero, L. Latapie, R. Richard, C. Andriantsiferana
This work reports the performance of a sequential adsorption/photocatalysis process using activated carbon fibers with deposited TiO2 for the elimination of the antibiotic ciprofloxacin (CIP) in water. A commercial activated carbon fiber (ACF10) was selected as the support, and a TiO2 coating was synthesized using Metal Organic Chemical Vapor Deposition (MOCVD). Experiments were carried out using a photocatalytic reactor irradiated with monochromatic LEDs (365nm). Two different processes have been studied: adsorption/photolysis and adsorption/photocatalysis. The objective was to completely remove the CIP and to evaluate the efficiency of the treatment by following the formation/elimination of aromatic transformation products (ATPs), aliphatic acids, fluoride, and the TOC in the liquid phase. The adsorption kinetic of the CIP by ACF10 was rather slow (71% of CIP adsorbed by 24 h and total adsorption by 20 days). A good fit between the external diffusion limitation model and the experimental curve (kext = 0.0056 h-1) showed an external transfer limitation due to a tight weave of fibers. For the adsorption/photolysis process, a significant decrease of the concentration was achieved (95% after 6 h of irradiation), but ten different ATPs were detected in the liquid phase. To eliminate CIP, 24 h of adsorption and 6 h of irradiation were then necessary, but most of the ATPs remained in solution (total treatment duration: 72 h). With ACF10-TiO2, the same ATPs were present in solution and were eliminated after the 6 h irradiation step (total treatment duration: 30 h). At the end of the treatment, several non-toxic aliphatic acids were found to be present, showing the higher efficiency of this sequential process. The presence of a significant amount of fluorine in the liquid phase suggests some surface photochemical reactions of the adsorbed molecules (CIP and transformation products) and a partial regeneration of the composite material.
{"title":"The Use of Composite TiO2/Activated Carbon Fibers as a Photocatalyst in a Sequential Adsorption/Photocatalysis Process for the Elimination of Ciprofloxacin","authors":"Thibaut Triquet, C. Tendero, L. Latapie, R. Richard, C. Andriantsiferana","doi":"10.21926/cr.2201007","DOIUrl":"https://doi.org/10.21926/cr.2201007","url":null,"abstract":"This work reports the performance of a sequential adsorption/photocatalysis process using activated carbon fibers with deposited TiO2 for the elimination of the antibiotic ciprofloxacin (CIP) in water. A commercial activated carbon fiber (ACF10) was selected as the support, and a TiO2 coating was synthesized using Metal Organic Chemical Vapor Deposition (MOCVD). Experiments were carried out using a photocatalytic reactor irradiated with monochromatic LEDs (365nm). Two different processes have been studied: adsorption/photolysis and adsorption/photocatalysis. The objective was to completely remove the CIP and to evaluate the efficiency of the treatment by following the formation/elimination of aromatic transformation products (ATPs), aliphatic acids, fluoride, and the TOC in the liquid phase. The adsorption kinetic of the CIP by ACF10 was rather slow (71% of CIP adsorbed by 24 h and total adsorption by 20 days). A good fit between the external diffusion limitation model and the experimental curve (kext = 0.0056 h-1) showed an external transfer limitation due to a tight weave of fibers. For the adsorption/photolysis process, a significant decrease of the concentration was achieved (95% after 6 h of irradiation), but ten different ATPs were detected in the liquid phase. To eliminate CIP, 24 h of adsorption and 6 h of irradiation were then necessary, but most of the ATPs remained in solution (total treatment duration: 72 h). With ACF10-TiO2, the same ATPs were present in solution and were eliminated after the 6 h irradiation step (total treatment duration: 30 h). At the end of the treatment, several non-toxic aliphatic acids were found to be present, showing the higher efficiency of this sequential process. The presence of a significant amount of fluorine in the liquid phase suggests some surface photochemical reactions of the adsorbed molecules (CIP and transformation products) and a partial regeneration of the composite material.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130283172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Mettu, Ninad Loke, Vilas A. Patil, Rahul Panday, Sreenivasarao Gajula
In this study, we present selective hydrocracking of poly (di and tri) aromatic compounds to monoaromatics, such as benzene, toluene, and xylenes (BTX), over a mixture of Pt/Al2O3 and Y zeolites. The polyaromatic compounds feed is a combined simulated model feed, which is similar to light cycle oil (LCO) in composition. The feed is processed in a fixed bed reactor over a catalyst mixture: in the first step, selective hydrogenation of di and tri-aromatic compounds occurs in the presence of Pt/Al2O3 catalyst, followed by conversion of selective hydrocracking of partial hydrogenated polyaromatic hydrocarbons into BTX-rich stream over Y zeolite. The structural properties and Pt dispersion of Pt/Al2O3 were studied by X-ray powder diffraction (XRD) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The acidity of Y zeolite with different SiO2/Al2O3 ratios (SAR) was studied by temperature-programmed desorption of NH3 (NH3-TPD). In addition, the textural properties of catalysts were determined using the N2 adsorption and desorption method. Different parameters such as the effect of temperature, effect of weight hourly space velocity (WHSV), different SAR of Y zeolite, Pt/Al2O3, and Y zeolite wt% ratios, and paraffin concentration were investigated. The maximum BTX yield of ~28 wt.% was obtained at 450°C, WHSV-0.7 h-1, H2 pressure 60 bar, Pt/Al2O3, and Y zeolite ratios of 1:2 (wt%) at Y zeolite SAR of 80. These results suggest that the yield of BTX strongly depends on the hydrogenation function (Pt/Al2O3) and acidity function of Y zeolite. Furthermore, the concentration of paraffin plays a key role in the conversion of diaromatics and triaromatics and desired products of BTX formation.
在这项研究中，我们展示了在Pt/Al2O3和Y沸石的混合物上，聚(二和三)芳香族化合物选择性加氢裂化成单芳香族化合物，如苯、甲苯和二甲苯(BTX)。多芳香族化合物饲料是一种组合模拟模型饲料，其组成与轻循环油(LCO)相似。进料在固定床反应器中通过催化剂混合物进行处理:第一步，在Pt/Al2O3催化剂的存在下，二芳香烃和三芳香烃进行选择性加氢，然后在Y沸石上将部分加氢的多芳香烃转化为富含btx的流。采用x射线粉末衍射仪(XRD)和高角环形暗场扫描透射电镜(HAADF-STEM)研究了Pt/Al2O3的结构性能和分散性。采用程序升温解吸法(NH3- tpd)研究了不同SiO2/Al2O3比(SAR)的Y型沸石的酸性。此外，用氮气吸附解吸法测定了催化剂的结构性质。考察了温度、质量时空速(WHSV)、Y型沸石的不同合成孔径(SAR)、Pt/Al2O3、Y型沸石wt%比、石蜡浓度等参数的影响。在450℃，WHSV-0.7 h-1, H2压力60 bar, Pt/Al2O3, Y沸石比为1:2 (wt%)， Y沸石SAR为80的条件下，BTX产率可达~28 wt.%。这些结果表明，BTX的产率很大程度上取决于Y型沸石的加氢功能(Pt/Al2O3)和酸性功能。此外，石蜡的浓度对二芳和三芳的转化以及BTX生成的期望产物起着关键作用。
{"title":"Hydrocracking of Di-and Triaromatic Hydrocarbons to Monoaromatics over Mixed Bi-functional Catalysts","authors":"A. Mettu, Ninad Loke, Vilas A. Patil, Rahul Panday, Sreenivasarao Gajula","doi":"10.21926/cr.2203021","DOIUrl":"https://doi.org/10.21926/cr.2203021","url":null,"abstract":"In this study, we present selective hydrocracking of poly (di and tri) aromatic compounds to monoaromatics, such as benzene, toluene, and xylenes (BTX), over a mixture of Pt/Al2O3 and Y zeolites. The polyaromatic compounds feed is a combined simulated model feed, which is similar to light cycle oil (LCO) in composition. The feed is processed in a fixed bed reactor over a catalyst mixture: in the first step, selective hydrogenation of di and tri-aromatic compounds occurs in the presence of Pt/Al2O3 catalyst, followed by conversion of selective hydrocracking of partial hydrogenated polyaromatic hydrocarbons into BTX-rich stream over Y zeolite. The structural properties and Pt dispersion of Pt/Al2O3 were studied by X-ray powder diffraction (XRD) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The acidity of Y zeolite with different SiO2/Al2O3 ratios (SAR) was studied by temperature-programmed desorption of NH3 (NH3-TPD). In addition, the textural properties of catalysts were determined using the N2 adsorption and desorption method. Different parameters such as the effect of temperature, effect of weight hourly space velocity (WHSV), different SAR of Y zeolite, Pt/Al2O3, and Y zeolite wt% ratios, and paraffin concentration were investigated. The maximum BTX yield of ~28 wt.% was obtained at 450°C, WHSV-0.7 h-1, H2 pressure 60 bar, Pt/Al2O3, and Y zeolite ratios of 1:2 (wt%) at Y zeolite SAR of 80. These results suggest that the yield of BTX strongly depends on the hydrogenation function (Pt/Al2O3) and acidity function of Y zeolite. Furthermore, the concentration of paraffin plays a key role in the conversion of diaromatics and triaromatics and desired products of BTX formation.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130772923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The kinetics of dearomatization of a kerosene fraction processed using a zeolite catalyst (0.9 HZSM-5) at different temperatures (160-200°C), the molar ratio between the aromatic hydrocarbons present in the kerosene fraction and n-decene (1:(0.5-4)), and the reaction time (1-3 h) were studied. Based on the obtained data, a kinetic model for kerosene dearomatization is proposed. It is assumed that the single-center Riedel mechanism is followed. The stage associated with the interaction between n-decene adsorbed on the surface of the catalyst containing aromatic compounds and n-decene present in the volume is identified as the limiting sage of the dearomatization process.
{"title":"Dearomatization of the Kerosene Fraction: Kinetic Studies","authors":"Sabira Sabir Ismayilova, S. Amirov","doi":"10.21926/cr.2202017","DOIUrl":"https://doi.org/10.21926/cr.2202017","url":null,"abstract":"The kinetics of dearomatization of a kerosene fraction processed using a zeolite catalyst (0.9 HZSM-5) at different temperatures (160-200°C), the molar ratio between the aromatic hydrocarbons present in the kerosene fraction and n-decene (1:(0.5-4)), and the reaction time (1-3 h) were studied. Based on the obtained data, a kinetic model for kerosene dearomatization is proposed. It is assumed that the single-center Riedel mechanism is followed. The stage associated with the interaction between n-decene adsorbed on the surface of the catalyst containing aromatic compounds and n-decene present in the volume is identified as the limiting sage of the dearomatization process.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130615928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, research on converting biomass platform compounds into high-value chemicals and pharmaceutical intermediates has garnered huge interest. Nitrile and amide groups are key structures in natural products and biologically active molecules. The direct conversion of biomass platform compounds into nitriles and amides will undoubtedly be an important guide for biomass utilization. In this paper, a facile and efficient triphosgene-assisted one-pot conversion for aldehydes and ketones into nitrile and amides is presented. Triphosgene is a phosgene alternative that contains both ester linkage and chloromethyl units and easily reacts with oximes for the preparation of nitriles and amides. However, due to the hydrolysis of oximes to aldehydes or ketones, the reaction of oximes with triphosgene cannot fully convert the corresponding nitriles and amides. The protocol tandem ensures a smooth process without the use of organic bases or metal catalysts. Using biomass-derived platform compounds, various functionalized aromatic, aliphatic, and allylic aldehydes and ketones were successfully converted to nitriles and amides in excellent yields. In comparison to step-by-step reactions, this tandem strategy features multi-step reactions in one pot, mild reaction conditions, and fewer by-products.
{"title":"One-Pot Tandem Synthesis of Nitriles and Amides from Biomass Platform Compounds","authors":"Xiuming Wei, Jianguo Liu, Longlong Ma","doi":"10.21926/cr.2201004","DOIUrl":"https://doi.org/10.21926/cr.2201004","url":null,"abstract":"In recent years, research on converting biomass platform compounds into high-value chemicals and pharmaceutical intermediates has garnered huge interest. Nitrile and amide groups are key structures in natural products and biologically active molecules. The direct conversion of biomass platform compounds into nitriles and amides will undoubtedly be an important guide for biomass utilization. In this paper, a facile and efficient triphosgene-assisted one-pot conversion for aldehydes and ketones into nitrile and amides is presented. Triphosgene is a phosgene alternative that contains both ester linkage and chloromethyl units and easily reacts with oximes for the preparation of nitriles and amides. However, due to the hydrolysis of oximes to aldehydes or ketones, the reaction of oximes with triphosgene cannot fully convert the corresponding nitriles and amides. The protocol tandem ensures a smooth process without the use of organic bases or metal catalysts. Using biomass-derived platform compounds, various functionalized aromatic, aliphatic, and allylic aldehydes and ketones were successfully converted to nitriles and amides in excellent yields. In comparison to step-by-step reactions, this tandem strategy features multi-step reactions in one pot, mild reaction conditions, and fewer by-products.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122438921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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