Article
Chemistry, Physical
Xinde Sun, Yue Yang, Yanli He, Shukui Zhu, Zhongmin Liu
Summary: By optimizing Si/Al ratio and hydrothermal treatment temperature, a high performance HZSM-5 catalyst was developed for liquid phase dehydration of methanol to dimethyl ether (DME). During a long term test of 6788 hours, DME selectivity remained above 99.96% with only slight deactivation observed, primarily attributed to coking and decline of HZSM-5 crystallinity.
Article
Chemistry, Applied
Miao Yu, Tianyu Mo, Hongyan Li, Songnan Li, Bin Lu, Jingxiang Zhao, Qinghai Cai
Summary: In this study, the surface acidity-basicity of NaZSM-5 was adjusted by simple impregnation in Fe3+ solution, leading to successful dehydration of methanol at lower reaction temperature with a conversion rate of over 90% and a selectivity of 100%. The acidic and basic sites on the catalyst surface were identified as the active sites, and the methanol adsorption behavior revealed the catalytic role of the acid-base balance. Furthermore, the catalyst showed super high stability without coke generation after continuous running for 500 hours.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Energy & Fuels
Fatima Magzoub, Shane Lawson, Fateme Rezaei, Ali A. Rownaghi
Summary: Additive manufacturing, also known as 3D printing, was used to produce customizable heterogeneous catalysts for the conversion of methanol into dimethyl ether. Among the catalysts tested, the one containing 4 wt % Ga2O3 alongside ZSM-5 showed the best performance at 200 degrees C, achieving 85% methanol conversion and 74% DME selectivity.
Article
Engineering, Environmental
Alireza Lotfollahzade Moghaddam, Melanie Jane Hazlett
Summary: Environmental pollution and global warming have become urgent issues worldwide. To tackle these issues, renewable and sustainable energy resources are needed, such as dimethyl ether (DME) which can be derived from syngas and CO2. Bi-functional catalysts have been studied to directly synthesize DME and improve the efficiency compared to the conventional indirect process. Different reactors and solid acid catalysts for methanol dehydration in both direct and indirect processes have been discussed. Factors affecting the catalyst performance, such as particle size, pore structures, and preparation methods, have also been reviewed. The thermodynamically preferable direct route should be further investigated and modified to overcome the challenges posed by water and optimize operational conditions.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Chemistry, Applied
Tomas Cordero-Lanzac, Cristina Martinez, Andres T. Aguayo, Pedro Castano, Javier Bilbao, Avelino Corma
Summary: This study investigates the synergies between oxygenates (especially dimethyl ether) and n-pentane at low OX/nC(5) ratios, enhancing n-pentane conversion while reducing catalyst coking rate. The analysis of used catalysts reveals that dimethyl ether exhibits higher reactivity than methanol in forming coke structures.
Article
Energy & Fuels
Saeed Sahebdelfar, Parisa Moghimpour Bijani, Fereydoon Yaripour
Summary: The kinetics of deactivation of gamma-alumina catalyst in the dehydration of methanol to dimethyl ether were investigated, revealing a second-order independent deactivation kinetics that accurately fit the experimental data. The activation energies for the main reaction and catalyst deactivation were obtained, with the latter showing a negative value due to reversible partial hydration. At higher temperatures, irreversible sintering of alumina crystallites became the predominant deactivation mechanism.
Article
Energy & Fuels
M. A. Armenta, V. M. Maytorena, R. Silva-Rodrigo, L. A. Flores-Sanchez, J. M. Quintana, A. Olivas
Summary: In this study, a low-cost synthesis method was used to prepare the Fe2O3/????Al2O3 catalyst, which showed a significant improvement in methanol dehydration conversion rate and selectivity towards DME. The Fe2O3/????Al2O3 catalyst exhibited a stable structure and low activation energy, making it a promising candidate for methanol dehydration under specific conditions.
Article
Energy & Fuels
L. N. Vosmerikova, Z. M. Matieva, Yu M. Snatenkova, N. Kolesnichenko, V. Zaikovskii, A. V. Vosmerikov
Summary: Zinc-isomorphously substituted HZSM-5 catalyst (Zn/HZSM-5(iso)) exhibits high selectivity and efficiency in the conversion of a mixture of DME + syngas.
Article
Multidisciplinary Sciences
Shanfan Lin, Yuchun Zhi, Zhiqiang Liu, Jiamin Yuan, Wenjuan Liu, Wenna Zhang, Zhaochao Xu, Anmin Zheng, Yingxu Wei, Zhongmin Liu
Summary: This study reveals the multiscale dynamical cross-talk in zeolite-catalyzed methanol and dimethyl ether conversions, emphasizing the importance of optimal spatiotemporal cooperation of diffusion-reaction-material for zeolite catalysis and process application. The research provides a comprehensive understanding of the dynamical diffusion and reaction process, crucial for zeolite shape-selective catalysis, and urgently demanded in academia and industry.
NATIONAL SCIENCE REVIEW
(2022)
Article
Engineering, Chemical
Tianyu Mo, Miao Yu, Hongyan Li, Songnan Li, Bin Lu, Jingxiang Zhao, Qinghai Cai
Summary: CrOx nanoparticle-and H+-modified NaZSM5 composites were prepared and characterized. The composites showed moderate surface acidity and basicity, resulting from the substitution of Cr species or H+ for counter Na+ and the highly dispersed CrOx nanoparticles on zeolites. The composites exhibited excellent performance in catalyzing methanol dehydration to dimethyl ether, with over 90% conversion and nearly 100% selectivity at lower reaction temperature. The activity remained stable over 500 hours of continuous operation, indicating excellent running stability.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Multidisciplinary Sciences
Aisyah Ardy, Dwi Hantoko, Jenny Rizkiana, Melia Laniwati Gunawan, Mi Yan, Herri Susanto
Summary: This study aimed to investigate the effect of phosphorus addition on the γ-Al2O3 catalyst for methanol dehydration to DME synthesis. The results showed that the 5%P/gamma-Al2O3 catalyst exhibited good performances with medium acidity for the dehydration of methanol to DME.
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
(2023)
Article
Engineering, Chemical
Wenzhe Yue, Zheng Wan, Yanhong Li, Xiao He, Juergen Caro, Aisheng Huang
Summary: This study successfully fabricated a novel Cu-ZnO-Pt@HZSM-5 catalytic membrane reactor, achieving high conversion and selectivity of CO2 hydrogenation to DME. By continuous separation of the by-product steam and removal of water, the issues of thermodynamic equilibrium and water-induced catalyst degradation were resolved.
JOURNAL OF MEMBRANE SCIENCE
(2022)
Article
Energy & Fuels
M. A. Armenta, Luis H. Alvarez, V. M. Maytorena, D. A. Buentello-Montoya, R. Silva-Rodrigo, A. Olivas, L. A. Flores-Sanchez
Summary: The wet impregnation method was used to support Ag2O, CuO, and Ag2O-CuO nanoparticles on gamma-chi-Al2O3 to evaluate their catalytic capabilities in the methanol dehydration (MD) reaction for dimethyl ether (DME) production. The Ag2O-CuO/gamma-chi-Al2O3 catalyst showed high catalytic activity and stability.
Article
Green & Sustainable Science & Technology
Betul Seker, Azam Khodadadi Dizaji, Volkan Balci, Alper Uzun
Summary: The study explored the performance of a mixed TPA/MCM-41 catalyst with a commercial CuO-ZnO Al2O3 catalyst in dimethyl ether synthesis through CO2 hydrogenation. By optimizing the loading and mixing ratios, a high DME synthesis rate was achieved under specific reaction conditions. The results demonstrated the potential of TPA/MCM-41 as an acid function in the catalyst mixture for efficient DME synthesis.
Article
Chemistry, Multidisciplinary
Zhixin Li, Yukun Shi, Di Liu, Shengjie Song, Liu Zhao, Ying Guo, Lidong Chen, Xiangsheng Wang, Xinwen Guo, Weiguo Cheng
Summary: Significant progress has been made in developing a new catalyst and utilizing single-stage reactor for efficient hydrorefining of FCC gasoline, resulting in high-quality fuel that meets the National standard VI of vehicle gasoline in China. The synergistic effect between Ni(ii) and HPW(iii) on nanocrystalline HZSM-5 zeolite contributes to the improved catalytic performance of the NiPW-Nano-Z catalyst.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Walaa Alharbi, Iftekhar Hassan, Rais Ahmad Khan, Shazia Parveen, Khadijah H. Alharbi, Ibtisam I. Bin Sharfan, Ibrahim M. Alhazza, Hossam Ebaid, Ali Alsalme
Summary: Biocompatible tryptophan-derived copper and zinc complexes were designed, synthesized, and evaluated for potential anticancer activity in vitro and in vivo. The results demonstrated decent selectivity and regulation of oxidative stress pathways in cancer cells.
Article
Energy & Fuels
Khurram Liaqat, Srosh Fazil, Wajid Rehman, Shaukat Saeed, Farid Menaa, Syed Asim Hussain Shah, Muhammad Nawaz, Walaa Naji Alharbi, Bouzid Menaa, Muhammad Farooq
Summary: By introducing a pendant group, a novel sulfonated polyimide with superior performance in hydrolytic stability, proton conductivity, and hydrophilicity was successfully synthesized.
Article
Chemistry, Multidisciplinary
Faizan Abul Qais, Mohammad Shavez Khan, Iqbal Ahmad, Fohad Mabood Husain, Rais Ahmad Khan, Iftekhar Hassan, Syed Ali Shahzad, Walaa AlHarbi
Summary: This study demonstrated the significant inhibitory effect of coumarin on QS-regulated virulent traits of Gram-negative bacteria, including the suppression of various virulence factors and biofilm formation. Computational studies revealed that coumarin may inhibit quorum sensing activity through multiple mechanisms.
Article
Polymer Science
Ali H. Bashal, Sayed M. Riyadh, Walaa Alharbi, Khadijah H. Alharbi, Thoraya A. Farghaly, Khaled D. Khalil
Summary: This study focuses on the preparation of nanocatalysts by doping zinc oxide nanoparticles within a chitosan matrix at different weight percentages. The nanocomposite film shows changes in structural features and proves to be an effective and recyclable base catalyst for the synthesis of thiazoles. The results demonstrate the potential of the nanocomposite film to be used multiple times in catalytic reactions without losing its catalytic activity.
Article
Engineering, Electrical & Electronic
A. A. Menazea, Eman Alzahrani, Walaa Alharbi, Abdallah A. Shaltout
Summary: The study investigates synthesizing Au/Ag nanoparticles using laser ablation and embedding them in chitosan. Results show that chitosan embedded with a 2/3 ratio of Au/Ag nanoparticles exhibits good electrical conductivity and antibacterial behavior. Fourier transform infrared analysis confirms the interaction and compatibility between chitosan chains and nanoparticles. The study suggests that 2/3 Au/Ag nanoparticles have potential antibacterial properties against both gram-negative and gram-positive bacteria.
JOURNAL OF ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Physical
Mai S. A. Hussien, Abdelfatteh Bouzidi, Hisham S. M. Abd-Rabboh, Ibrahim S. Yahia, Heba Y. Zahran, Mohamed Sh. Abdel-wahab, Walaa Alharbi, Nasser S. Awwad, Medhat A. Ibrahim
Summary: The incorporation of tungsten trioxide (WO3) into graphitic carbon nitride (g-C3N4) was studied, and the morphology, microstructure, optical properties, and photocatalytic activity of the composite photocatalyst were analyzed. The results showed that the particle size of the photocatalyst was affected by the incorporation of WO3, but the bandgap energy remained unchanged.
Article
Chemistry, Multidisciplinary
M. A. El-Morsy, Nasser S. Awwad, Hala A. Ibrahium, Walaa Alharbi, Mohammad Y. Alshahrani, A. A. Menazea
Summary: A ternary nanocomposite (TNC) was fabricated to introduce multifunctional properties for various biomedical applications. The TNC, composed of hydroxyapatite (HAP), graphene oxide (GO), and gadolinium oxide (Gd2O3), exhibited suitable physical properties and surface characteristics according to morphological and topological studies. In vitro experiments also demonstrated its excellent biocompatibility.
JOURNAL OF SAUDI CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Mohamed A. Farghali, Abdelfattah M. Selim, Hanem F. Khater, Noha Bagato, Walaa Alharbi, Khadijah H. Alharbi, Ibrahim Taha Radwan
Summary: This study examined the adsorption effectiveness of MgAl-layered double hydroxide (MgAl-LDH) nanosorbents on Congo red (CR) dye in aqueous solutions. The adsorption parameters and physicochemical characteristics of the synthesized MgAl-LDH were investigated, and the results showed rapid adsorption and high adsorption capacity for the CR dye.
ARABIAN JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Sikandar Khan, Mian Muhammad, Hamed M. Al-Saidi, Athar Abdulfattah Hassanian, Walaa Alharbi, Khadijah H. Alharbi
Summary: A novel thiazole-based Schiff base chemosensor SB1 was synthesized and characterized, and it demonstrated high selectivity and sensitivity towards Cu2+ ions. The sensor showed significant spectral changes and colorimetric response, and it can be used for the detection of trace amounts of Cu2+ ions in various samples.
JOURNAL OF SAUDI CHEMICAL SOCIETY
(2022)
Article
Polymer Science
Khaled D. Khalil, Sayed M. Riyadh, Nazeeha S. Alkayal, Ali H. Bashal, Khadijah H. Alharbi, Walaa Alharbi
Summary: In this study, strontium oxide-chitosan nanocomposites were synthesized using a microwave-assisted solution casting approach. The nanocomposites were characterized using FTIR, XRD, and SEM, and the results confirmed the formation of chitosan-strontium oxide nanocomposites. The CS-SrO nanocomposite showed high catalytic efficiency and favorable reaction conditions.
Article
Environmental Sciences
Mian Muhammad, Sikandar Khan, Gul Rahim, Walaa Alharbi, Khadijah H. Alharbi
Summary: A sensitive, selective, and simple spectrofluorimetric method based on thioglycolic acid-caped Mn-doped ZnS quantum dots was developed for the detection and determination of cypermethrin. The synthesized quantum dots were structurally characterized and the fluorescence quenching of the quantum dots showed a linear relationship with the concentration of cypermethrin. The method was successfully applied for the detection and determination of cypermethrin in various spiked samples.
ENVIRONMENTAL MONITORING AND ASSESSMENT
(2022)
Article
Polymer Science
Khadijah H. Alharbi, Walaa Alharbi, M. A. El-Morsy, M. O. Farea, A. A. Menazea
Summary: The study investigates the mixing of polyvinyl pyrrolidine/carboxymethyl cellulose (PVP/CMC) with different quantities of tungsten-trioxide nanoparticles (WO3 NPs). Samples were prepared using the casting method and Pulsed Laser Ablation (PLA). Various analysis techniques were employed to examine the samples. Results show a semi-crystalline nature of PVP/CMC, confirmed by the XRD analysis. FT-IR spectra indicate shifts in band locations and changes in intensity with the incorporation of WO3. UV-Vis spectra indicate a decrease in optical band gap with increased laser-ablation time. TGA curves demonstrate improved thermal stability of the samples. AC conductivity of the composite films was determined, with an increase in both (epsilon') and (epsilon'') observed with higher content of tungsten trioxide. The incorporation of tungsten trioxide enhances the ionic conductivity of PVP/CMC/WO3 nano-composite to a maximum of 10(-8) S/c. The findings of this study have significant implications for applications such as energy storage, polymer organic semiconductors, and polymer solar cells.
Article
Polymer Science
Naheed Akhtar, Naveed Akhtar, Farid Menaa, Walaa Alharbi, Fatima Saad Salem Alaryani, Ali Musfer Alqahtani, Faizan Ahmad
Summary: Tocopherol acetate (TA) is a skin moisturizing and photoprotective agent, but its stability is limited. In this study, a highly stable TA-containing ethosomal gel (TAEG) was successfully developed using a cold method technique. Extensive in vitro evaluations and characterization were performed, and the optimized TAEG formulation (TA-5) showed the highest entrapment efficiency and stability, as well as improved drug permeation in ex vivo experiments.
Article
Chemistry, Inorganic & Nuclear
Mohammad Usman, Rais Ahmad Khan, Mohammad Rashid Khan, Mohammad Abul Farah, Ibtisam I. BinSharfan, Walaa Alharbi, Jilani. P. Shaik, Narasimha Reddy Parine, Ali Alsalme, Sartaj Tabassum
Summary: Copper compounds show potential as next-generation metal anticancer drugs, with a newly synthesized polymer displaying high DNA binding propensity and selective cytotoxicity against A549 cancer cells. In vitro studies also revealed the polymer's ability to cleave DNA and its impact on gene expression in various cell lines.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Multidisciplinary
Mohammad Usman, Fohad Mabood Husain, Rais Ahmad Khan, Walaa Alharbi, Ali Alsalme, Hamad A. Al-Lohedan, Sartaj Tabassum
Summary: Novel ruthenium arene complexes of flavonoid derivatives were synthesized and tested against pathogens, showing potential as biofilm and quorum sensing inhibitors. Microscopic observations revealed biofilm inhibition and reduced microcolonies.
NEW JOURNAL OF CHEMISTRY
(2021)
