Article
Chemistry, Physical
J. Pablo Martinez, Bartosz Trzaskowski
Summary: In this study, we investigated the stereoselectivity of cross metathesis reaction using computational methods and obtained results consistent with experimental observations. The evaluation of structural strain provided insights into the design of stereoselective catalysts.
CATALYSIS COMMUNICATIONS
(2022)
Article
Chemistry, Applied
Yong Wang, Toshiyuki Yokoi, Takashi Tatsumi
Summary: Compared to conventional steam cracking, catalytic cracking of naphtha and methanol-to-olefins (MTO) over zeolite catalysts have been proven as the most successful processes for producing light olefins. In this review, the impacts of topology, acidity, and particle size of zeolites on the catalytic performance of naphtha cracking and MTO reactions, especially the light olefins selectivity and lifetime are systematically discussed. The goal is to provide a deeper understanding of the structure-property-performance relationship of various zeolite catalysts and facilitate the design of more excellent zeolite catalysts for these two processes.
MICROPOROUS AND MESOPOROUS MATERIALS
(2023)
Article
Chemistry, Organic
A. I. Nikiforov, E. A. Chesnokov, A. G. Popov, I. A. Nikiforov, I. I. Ivanova
Summary: Supported catalysts Mo/Al2O3 modified with (NH4)(2)SiF6 and H3BO3 were synthesized and tested for the metathesis of propylene. The support modifications had different effects on the catalyst acidity, with (NH4)(2)SiF6 not altering it while the interaction with boric acid increased the acidity. Dual modification with both (NH4)(2)SiF6 and H3BO3 enhanced the catalyst activity but led to faster deactivation.
PETROLEUM CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Zi-Yuan Wang, Rong Zhu
Summary: This study presents a middle meet strategy to synthesize high-molecular-weight, stable, and solution-processable conjugated cumulene polymers. The stability-conjugation dilemma is successfully addressed and electronic communication between cumulene units is found to be dependent on the aromaticity of the pi-spacers, allowing for flexible energy-level adjustment and the synthesis of narrow band gap polymers.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Xing Chen, Xiao-Ting Wang, Jia-Bo Le, Shu-Min Li, Xue Wang, Yu-Jin Zhang, Petar Radjenovic, Yu Zhao, Yao-Hui Wang, Xiu-Mei Lin, Jin-Chao Dong, Jian-Feng Li
Summary: Ruthenium shows comparable or even better activity than platinum for alkaline hydrogen evolution reaction, but its mechanistic aspects are not yet resolved. In this study, in situ Raman spectroscopy and theoretical calculations are combined to elucidate the dynamic spectral evidence of Ru surfaces, interfacial water, *H, and *OH intermediates. The different valence states of Ru surfaces, as well as the hydrated Na+ ion water and high-valence Ru(n+) surfaces, contribute to the dissociation of interfacial water and the generation of two distinct *H, leading to different activities. The regulation of valence state on interfacial water, intermediates, and catalytic activity provides guidelines for the rational design of high-efficiency catalysts.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Muqian Deng, Max Wilde, John T. T. Welch
Summary: The cross-metathesis reactions of CF3SF4-substituted primary alkene and 3-CF3SF4-propene were successfully catalyzed by a second-generation Hoveyda-Grubbs catalyst under mild conditions (room temperature), resulting in good yield. CF3SF4-propene also underwent cross metathesis with substrates containing electron-withdrawing or electron-donating groups at room temperature or under dichloromethane reflux. The formation of the CF3SF4-propene homodimer and its application in selective cross-metathesis reactions were discussed.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Shanqing Yu, Jiasong Yan, Wei Lin, Jun Long, Shang-Bin Liu
Summary: Understanding the role of rare earth in catalysts is crucial for improving performance in petrochemical industry. La-incorporated Y zeolites exhibit enhanced stability and acidity, leading to increased heavy oil conversion but decreased olefins and coke selectivity. Adjusting La2O3 content is important for enhancing cracking ability while optimizing selectivity.
Article
Chemistry, Multidisciplinary
Meng Li, Yelena Kan, Hang Su, Ulrich Poschl, Sapun H. Parekh, Mischa Bonn, Yafang Cheng
Summary: Acidity is crucial for atmospheric aerosol formation and its impacts on air quality, climate, and the ecosystem. This study directly measures the pH distribution in NaH2PO4-Na2HPO4 microdroplets and finds that the pH values of the microdroplets are similar to the parent bulk solutions and remain constant across the microdroplets. Similar results are observed for acidic NaHSO4 microdroplets.
Article
Chemistry, Multidisciplinary
Marcel-Philip Luecke, Shenglai Yao, Matthias Driess
Summary: Two new ligands were synthesized and studied, one of which demonstrated high catalytic activity in the hydrogenation of olefins under mild conditions, achieving the highest performance of a homogeneous nickel-based catalyst. The coordination mode of the Ni(0) site by the intramolecular phenylene was found to play a crucial role in the catalytic activity, as revealed by kinetic measurements and correlation experiments.
Article
Chemistry, Organic
Maria Kourgiantaki, Vera P. Demertzidou, Alexandros L. Zografos
Summary: In this study, the oxy-Cope/ene reaction cascade was used to form a locked elemane conformer, enabling the short and scalable synthesis of versatile Apiaceae scaffolds. The divergent fate of the obtained macrocyclic germacrane was explored under different reaction conditions, leading to the diastereoselective synthesis of oxidized Apiaceae guaiane congeners and the total synthesis of 4-epi-epiguaidiol A. Additionally, the reduction of a hydrogen-bond-biased guaiane substrate allowed for the chemoselective synthesis of desoxo-jungiaguaiane.
Article
Chemistry, Analytical
Wei Huang, Desheng Fan, Wangfang Li, Yaoyong Meng, Timon Cheng-yi Liu
Summary: This study proposes a rapid and non-destructive method for evaluating milk acidity based on Raman spectroscopy and chemometrics. It utilizes nonlinear modeling to predict the acidity and can detect illegal neutralization of milk acidity.
VIBRATIONAL SPECTROSCOPY
(2022)
Article
Chemistry, Multidisciplinary
Halenur Ozer, Dilan Arslan, Bengi Ozgun Ozturk
Summary: In this study, in situ formed ruthenium hydride species from Grubbs type catalysts were used as efficient catalysts for dehydrogenative alcohol coupling and sequential cross-metathesis/dehydrogenative coupling reactions. The selectivity of the catalysts can be tuned by using different bases to obtain different products. With the presence of a new ligand, the performance of the catalyst was significantly improved, yielding products in quantitative yields.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Green & Sustainable Science & Technology
Omvir Singh, Ankit Agrawal, Neha Dhiman, Bhanu Prasad Vempatapu, Ken Chiang, Shailendra Tripathi, Bipul Sarkar
Summary: The study investigated the transformation of jatropha oil into aromatics using bimetallic ZSM-5 catalyst in a continuous downflow reactor. The addition of Ce as a promoter was found to enhance dehydrodeoxygenation reaction and aromatic selectivity. The optimized catalyst 10Zn5Co5Ce/Z showed high conversion and aromatic selectivity with negligible coke deposition.
Article
Energy & Fuels
Jiajia Chen, Qiao Zhao, Xiaoxue Han, Jing Lv, Zhenhua Li, Shouying Huang, Xinbin Ma
Summary: The Fischer-Tropsch synthesis is an effective method for producing fuels and key chemicals from syngas. This study investigates the influence of the CO/H2 ratio on the performance of a precipitated iron catalyst. The results show that activation with a low CO/H2 ratio achieves a balance of CO dissociation and diffusion, leading to high conversion and selectivity of the catalyst.
Review
Chemistry, Multidisciplinary
Benedikt W. Grau, Alexander Neuhauser, Sadig Aghazada, Karsten Meyer, Svetlana B. Tsogoeva
Summary: Metathesis reaction is an important tool in synthetic chemistry that transforms hydrocarbon molecules through exchange of molecular fragments. There have been many modifications and improvements, including the use of iron as a catalyst.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
O. A. Ponomareva, P. A. Shaposhnik, V. Nazarova, D. S. Zasukhin, A. G. Popov, A. Efimov, I. I. Ivanova
Summary: This study investigates the effects of the degree of ion exchange on the physicochemical properties of FAU(Y) in terms of the sodium and cesium cations. The results show that NaY samples with varying exchange degrees can be prepared while maintaining the crystalline structure. The CsOH-modified catalysts with a Na+/Cs+ exchange degree of 54-77% exhibit the highest activity and stability in aniline alkylation with methanol.
PETROLEUM CHEMISTRY
(2022)
Article
Chemistry, Organic
A. Nikiforov, I. Babchuk, V. A. Vorobkalo, E. A. Chesnokov, D. L. Chistov
Summary: In this study, we used machine learning algorithms to predict the degree of crystallinity of zeolites based on the initial synthesis parameters. By analyzing a large number of research papers and creating a database, the gradient boosting algorithm with polynomial features achieved the highest accuracy in combination with the database processing rate.
PETROLEUM CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Maria G. Chernysheva, Artem V. Sinolits, Valeria S. Votyakova, Andrey G. Popov, Gennadii A. Badun
Summary: Hyaluronic acid shows potential as a coating to improve the biocompatibility of nanodiamond-antibiotic composites. The adsorption of hyaluronic acid is found to be higher on nanodiamonds with initially negative zeta-potential, after pre-adsorption of Miramistin, but still lower than on positively charged nanodiamonds unaffected by Miramistin. The maximum adsorption of hyaluronic acid is observed when Miramistin neutralizes the surface charge of nanoparticles.
MENDELEEV COMMUNICATIONS
(2022)
Article
Chemistry, Organic
I. A. Kasyanov, A. Efimov, A. G. Popov, A. L. Grachev, I. Dobryakova
Summary: This study investigated the development of submicron and nanocrystalline silicate materials with MFI structure in a fluorinated surfactant medium, using perfluorononanoic acid as an example. It was found that the crystal structure of the zeolite framework formed slower in fluorinated surfactants due to the presence of aluminum atoms. The fractions of Bronsted and Lewis acid sites in the synthesized zeolites were independent of the amount of aluminum introduced. Moreover, the synthesized zeolites with lower concentration of Bronsted acid sites and smaller crystal size showed similar activity and operational stability to commercially available catalysts in the oligomerization of light alkenes.
PETROLEUM CHEMISTRY
(2022)
Article
Chemistry, Organic
V. A. Vorobkalo, D. O. Bachurina, A. G. Popov, A. Efimov, I. I. Ivanova
Summary: In this study, MFI and MEL zeolites with different crystal sizes and close Si/Al ratios were successfully synthesized by hydrothermal crystallization. Pt was coated on the zeolites using incipient wetness impregnation. The results showed that the crystal size and zeolite structure had little effect on the product distribution in n-hexadecane dewaxing, but zeolites with larger crystals exhibited lower catalytic activity.
PETROLEUM CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Maria G. Chernysheva, Andrey G. Popov, Mikhail G. Dzianisik, Alexander V. Egorov, Tolganay B. Egorova, Alexander V. Gopin, Artem A. Mitrofanov, Gennadii A. Badun
Summary: Hydrogen treatment is a popular method for surface modification of nanodiamonds. In this study, atomic hydrogen treatment of the functionalized surface was used to gently increase its hydrophobicity and maintain its overall composition. The corresponding mechanism was revealed through a combination of theoretical and experimental methods.
MENDELEEV COMMUNICATIONS
(2023)
Article
Chemistry, Organic
A. L. Grachev, K. V. Maerle, A. I. Nikiforov, A. A. Maerle
Summary: Hierarchical oxides based on CeO2 and Al2O3 were prepared and characterized. The samples showed high specific surface area and different pore size. They were tested as catalysts for the synthesis of dimethyl carbonate, with different cerium content influencing their catalytic properties. Pure cerium(IV) oxide exhibited the highest activity and selectivity. The optimum reaction conditions were determined as 130 degrees C and a pressure of 5 MPa.
PETROLEUM CHEMISTRY
(2023)
Article
Chemistry, Organic
A. I. Nikiforov, E. A. Chesnokov, A. G. Popov, I. A. Nikiforov, I. I. Ivanova
Summary: Supported catalysts Mo/Al2O3 modified with (NH4)(2)SiF6 and H3BO3 were synthesized and tested for the metathesis of propylene. The support modifications had different effects on the catalyst acidity, with (NH4)(2)SiF6 not altering it while the interaction with boric acid increased the acidity. Dual modification with both (NH4)(2)SiF6 and H3BO3 enhanced the catalyst activity but led to faster deactivation.
PETROLEUM CHEMISTRY
(2023)
Article
Chemistry, Physical
Vladislav Gorbunov, Aleksey Buryak, Kirill Oskolok, Andrey G. Popov, Irina Tarkhanova
Summary: In this article, a series of effective catalysts based on betaine and sulfuric or phosphomolybdic acids were obtained. These compositions were characterized and tested in the oxidation of sulfur- and nitrogenous-containing compounds by H2O2. The acidity change is non-linearly influenced by the amount of heteropolyacid (HPA), and the removal of sulfur-containing compounds is correlated with the concentration of Bronsted acid sites on the catalyst surface. On the other hand, the removal of pyridine is primarily determined by the content of heteropolyacids in the catalyst.
Article
Chemistry, Organic
V. A. Artamonova, A. G. Popov, I. I. Ivanova
Summary: MEL zeolite synthesized by steam-assisted crystallization method showed high phase purity, large micropore volume, and high concentrations of acid sites. Its acidic properties were characterized by IR spectroscopy using probe molecules. In terms of catalytic performance, this zeolite proved to be comparable to MFI-type zeolites.
PETROLEUM CHEMISTRY
(2023)
Article
Chemistry, Physical
Tianyi Shen, Maria G. Chernysheva, Gennadii A. Badun, Andrey G. Popov, Alexander Egorov, Neli M. Anuchina, Ivan S. Chaschin, Natalia P. Bakuleva
Summary: The research found that nanodiamonds can form adsorption complexes with levofloxacin and amikacin, reducing the dose of antibiotics used and decreasing their use in the postoperative period.
COLLOIDS AND INTERFACES
(2022)
Article
Chemistry, Physical
Yifan Sun, Ye Lv, Wei Li, Jinli Zhang, Yan Fu
Summary: In this study, PtRu electrocatalysts were fabricated on carbon paper via cyclic electrodeposition for the electrocatalytic hydrogenation (ECH) of phenol. The Pt3Ru3 catalyst exhibited excellent activity and stability for the conversion of phenol to cyclohexanol at ambient temperature and various current densities. The in situ Raman spectroscopy and kinetic study revealed the hydrogenation mechanism of phenol over Pt3Ru3 in acidic electrolyte, providing an effective electrochemical strategy for the facile construction of durable electrode materials and efficient phenol hydrogenation.
JOURNAL OF CATALYSIS
(2024)
Article
Chemistry, Physical
Amir Shahzad, Khezina Rafiq, Muhammad Zeeshan Abid, Naseem Ahmad Khan, Syed Shoaib Ahmad Shah, Raed H. Althomali, Abdul Rauf, Ejaz Hussain
Summary: Photocatalytic hydrogen production through water splitting is an effective method for meeting future energy demands. In this study, researchers synthesized a 1 % Ag2S/Cu2S co-doped CdZnS catalyst and found that it can produce hydrogen at a higher rate. The co-doping of Ag2S and Cu2S in the CdZnS catalyst showed a synergistic effect, with Ag2S promoting oxidation reactions and Cu2S promoting reduction reactions.
JOURNAL OF CATALYSIS
(2024)
