Catalysts最新文献_第4页

Staphylococcus aureus Alkaline Protease: A Promising Additive for Industrial Detergents 金黄色葡萄球菌碱性蛋白酶：一种前景看好的工业洗涤剂添加剂

Catalysts Pub Date : 2024-07-12 DOI: 10.3390/catal14070446

Mona A Alonazi

{"title":"Staphylococcus aureus Alkaline Protease: A Promising Additive for Industrial Detergents","authors":"Mona A Alonazi","doi":"10.3390/catal14070446","DOIUrl":"https://doi.org/10.3390/catal14070446","url":null,"abstract":"A novel alkaline serine protease, derived from the Staphylococcus aureus strain ALA1 previously isolated from dromedary milk, was subjected to purification and characterization. Optimal protease production occurred under specific culture conditions. The purified protease, designated S. aureus Pr with a molecular mass of 23,662 Da and an N-terminal sequence, showed an approximately 89% similar identity with those of other Staphylococcus strains. It exhibited its highest enzymatic activity at a pH of 10.0 and 60 °C in the presence of 3 mM Ca2+. Remarkable thermostability was observed at temperatures up to 70 °C and within a pH range of 6.0 to 10.0 for 2 h. The presence of Ca2+ or Mg2+ and Zn2+ significantly enhanced both enzymatic activity and thermal stability. Additionally, notable stability was demonstrated in the presence of reducing and chaotropic agents as well as in surfactants, oxidizing agents, and organic solvents commonly found in detergent compositions. This highlights the enzyme’s potential as a versatile biocatalyst, especially in detergents. Its stability and compatibility with laundry detergents matched Alcalase 2.5 L, type Dx, and the Stearothermophilus protease, used as controls. Collectively, this study investigated the potential utilization of S. aureus Pr in industrial detergents as an excellent candidate for incorporation as an additive in detergent formulations.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"26 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141654329","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}

引用次数: 0

Structural Effect of Cu-Mn/Al2O3 Catalysts on Enhancing Toluene Combustion Performance: Molecular Structure of Polyols and Hydrothermal Treatment Cu-Mn/Al2O3 催化剂对提高甲苯燃烧性能的结构影响：多元醇的分子结构和水热处理

Catalysts Pub Date : 2024-07-11 DOI: 10.3390/catal14070443

Junjie Li, Wenjing Chen, Chenghua Xu, Xiaoxiao Hou, Xiaodong Hu

{"title":"Structural Effect of Cu-Mn/Al2O3 Catalysts on Enhancing Toluene Combustion Performance: Molecular Structure of Polyols and Hydrothermal Treatment","authors":"Junjie Li, Wenjing Chen, Chenghua Xu, Xiaoxiao Hou, Xiaodong Hu","doi":"10.3390/catal14070443","DOIUrl":"https://doi.org/10.3390/catal14070443","url":null,"abstract":"This study presents a series of Cu-Mn/Al2O3 catalysts prepared by the polyol method to improve the toluene combustion process. The catalytic activity evaluation results showed that the different polyols have a great influence on catalyst activity, in which the catalyst prepared with glycerol through a hydrothermal reaction at 90 °C displayed the highest catalytic activity. The lowest T90 and T50 values could be achieved by CMA-GL-90 with 260 and 237 °C, respectively. Moreover, the XRD and BET results showed that the hydrothermal treatment was more favorable with Cu-Mn crystal formation, and an abundance of mesopores remained in all catalysts with a high specific surface area from 94.37 to 123.03 m2·g−1. The morphology analysis results by SEM and TEM indicated that employing glycerol coupled with hydrothermal treatment at 90 °C could enhance the formation of CuMn2O4 spinel. The toluene catalytic combustion mechanism of Cu-Mn/Al2O3 catalysts was discussed based on XPS and H2-TPR, and a high atomic ratio of Mn3+ could be obtained with 51.03%, and the ratio of Oads/Olatt also increased to 2.85 in CMA-GL-90. The increase in Mn3+ species and oxygen vacancies on the surface of catalysts exhibited excellent activity and stability for toluene combustion. These findings offer valuable insights for optimizing the design and application of Cu-Mn/Al2O3 catalysts in addressing the catalytic oxidation reactions of organic volatile compounds.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"53 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141655703","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}

引用次数: 0

Mixed Oxides as Catalysts for the Condensation of Cyclohexanol and Benzaldehyde to Obtain a Claisen–Schmidt Condensation Product 混合氧化物作为环己醇和苯甲醛缩合生成克莱森-施密特缩合产物的催化剂

Catalysts Pub Date : 2024-07-11 DOI: 10.3390/catal14070445

Tanya Stoylkova, T. Stanimirova, C. D. Chanev, Petya Petrova, Kristina Metodieva

{"title":"Mixed Oxides as Catalysts for the Condensation of Cyclohexanol and Benzaldehyde to Obtain a Claisen–Schmidt Condensation Product","authors":"Tanya Stoylkova, T. Stanimirova, C. D. Chanev, Petya Petrova, Kristina Metodieva","doi":"10.3390/catal14070445","DOIUrl":"https://doi.org/10.3390/catal14070445","url":null,"abstract":"Acid–base M2+MgAlO and M2+AlO mixed oxides (where M2+ = Mg, Cu, Co, Zn, and Ni) were obtained by thermal decomposition of the corresponding layered double hydroxide (LDH) precursors and used as catalysts for cyclohexanol and benzaldehyde condensation under solvent-free conditions. The catalysts were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), and temperature-programmed desorption of CO2 (TPD-CO2). Gas chromatography–mass spectroscopy (GC/MS) was used for the identification and quantification of the product mixtures. In the reaction of cyclohexanol and benzaldehyde on M2+MgAlO and MgAlO catalysts, a 2,6-dibenzylidene-cyclohexanone was obtained as the main product as a result of consecutive one-pot dehydrogenation of cyclohexanol to cyclohexanone and subsequent Claisen–Schmidt condensation. In the reaction mixture obtained in the presence of NiAlO, CoAlO, and ZnAlO catalysts, a cyclohexyl ester of 6-hydroxyhexanoic acid was detected together with the main product. This is most likely a by-product obtained after the oxidation, ring opening, and subsequent esterification of the cyclohexanol.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141658602","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}

引用次数: 0

Nanocatalysts for the Degradation of Refractory Pollutants 降解难降解污染物的纳米催化剂

Catalysts Pub Date : 2024-07-11 DOI: 10.3390/catal14070444

Sheng Guo, Yazi Liu, Jun Li

引用次数: 0

Enhanced Photocatalytic Performances of SnS2/TiO2 Composites via a Charge Separation Following Z-Scheme at the SnS2/TiO2{101} Facets 通过 SnS2/TiO2{101} 表面 Z 型电荷分离提高 SnS2/TiO2 复合材料的光催化性能

Catalysts Pub Date : 2024-07-10 DOI: 10.3390/catal14070442

Nkenku Carl, Muhammad Fiaz, Hyun-Seok Oh, Yu-Kwon Kim

{"title":"Enhanced Photocatalytic Performances of SnS2/TiO2 Composites via a Charge Separation Following Z-Scheme at the SnS2/TiO2{101} Facets","authors":"Nkenku Carl, Muhammad Fiaz, Hyun-Seok Oh, Yu-Kwon Kim","doi":"10.3390/catal14070442","DOIUrl":"https://doi.org/10.3390/catal14070442","url":null,"abstract":"The formation of heterojunctions for efficient charge separation has been practiced for the preparation of efficient semiconductor-based photocatalysts for applications such as hydrogen production and environmental remediation. In this study, we synthesized a composite structure with a heterojunction between SnS2 and TiO2 through a microwave-assisted hydrothermal process, in which SnS2 nanoparticles grew on nanocrystalline TiO2 nanosheets preferentially at the exposed {101} facets. Appropriate exposure of the {001} and {101} facets of the TiO2 nanosheet in the composite with a preferential growth of SnS2 nanoparticles at the {101} facets was the origin of the charge separation following a direct Z-scheme mechanism to result in enhanced photocatalytic performances in photodegradation of organic dyes such as methylene blue (MB) and rhodamine B (RhB) compared to that of SnS2 and TiO2 alone. A plot of photodegradation rates vs. SnS2 ratios in the composites gave an overall volcano-shaped curve with a maximum at the SnS2 ratio of about 33% at which small SnS2 nanoparticles were populated at the {101} facets of the TiO2 nanosheets with a high surface area (118.2 m2g−1). Our results suggest the microwave-assisted hydrothermal process can be a good synthetic approach for composite-based photocatalysts with a preferential heterojunction structure.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"5 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141660819","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}

引用次数: 0

Tuning a Cr-Catalyzed Ethylene Oligomerization Product Profile via a Rational Design of the N-aryl PNP Ligands 通过合理设计 N-芳基 PNP 配体调谐铬催化乙烯低聚产物谱

Catalysts Pub Date : 2024-07-10 DOI: 10.3390/catal14070441

Samir Barman, E. Jaseer, Nestor Garcia, Mohamed Elanany, Motaz Khawaji, Niladri Maity, Abdulrahman Musa

引用次数: 0

Exclusive Review Papers in Catalytic Materials 催化材料》独家评论文章

Catalysts Pub Date : 2024-07-09 DOI: 10.3390/catal14070439

C. Belver

引用次数: 0

Autocatalyzed Kinetics of 6-Electron Electroreduction of Iodic Acid Studied by Rotating Disk Electrode Technique 旋转盘电极技术研究碘酸 6 电子电还原的自催化动力学

Catalysts Pub Date : 2024-07-09 DOI: 10.3390/catal14070437

Liliya Antipova, Oleg Tripachev, Alexandra Rybakova, Vladimir Andreev, R. Pichugov, George Sudarev, Anatoly Antipov, Alexander Modestov

{"title":"Autocatalyzed Kinetics of 6-Electron Electroreduction of Iodic Acid Studied by Rotating Disk Electrode Technique","authors":"Liliya Antipova, Oleg Tripachev, Alexandra Rybakova, Vladimir Andreev, R. Pichugov, George Sudarev, Anatoly Antipov, Alexander Modestov","doi":"10.3390/catal14070437","DOIUrl":"https://doi.org/10.3390/catal14070437","url":null,"abstract":"The 6-electron electrochemical reduction of IO3− to I− represents a breakthrough for the development of next-generation redox flow batteries, offering substantially higher energy densities for oxidizer storage. Our study reveals that on a glassy carbon (GC) electrode in acidic electrolytes, HIO3 undergoes an autocatalyzed electrochemical reduction to I−. This process is mediated by the formation of a thin iodine layer on the electrode, acting as an intermediate and a catalyst. Under steady-state conditions, the iodine layer forms via a comproportionation reaction (HIO3 + I− + 5H+ = I2 (s) + 3H2O). Initially, the iodine layer is generated through the slow direct electrochemical reduction of HIO3 on pristine GC. Once established, this layer significantly enhances the rate of iodate reduction. On voltammetry curves, it is clearly observable as a step-wise current surge to reach a plateau. The limiting current density on the GC seemingly aligns with the Levich equation, varying with the RDE rotation rate. Earlier, we demonstrated the electrochemical oxidation of I− back to HIO3 using an H2/HIO3 flow cell, showcasing a full cycle that underpins the feasibility of this approach for energy storage. This study advances the understanding of iodate electroreduction and underscores its role in enhancing the capacity of next-generation energy storage systems.","PeriodicalId":505577,"journal":{"name":"Catalysts","volume":"112 38","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141665703","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}

引用次数: 0

Theoretical Study of Reversible Hydrogenation of CO2 to Formate Catalyzed by Ru(II)–PN5P, Fe(II)–PN5P, and Mn(I)–PN5P Complexes: The Effect of the Transition Metal Center Ru(II)-PN5P、Fe(II)-PN5P 和 Mn(I)-PN5P 复合物催化 CO2 向甲酸的可逆氢化的理论研究：过渡金属中心的影响

Catalysts Pub Date : 2024-07-09 DOI: 10.3390/catal14070440

Lingqiang Meng, Lihua Yao, Jun Li

引用次数: 0

Advances in Transition Metal Catalysis—Preface to the Special Issue 过渡金属催化的进展--特刊序言

Catalysts Pub Date : 2024-07-09 DOI: 10.3390/catal14070438

A. Ciogli, Antonia Iazzetti

引用次数: 0