查找使用阿拉丁产品的科研文献

CuO-CeO2/ZSM-5 composites for reactive adsorption of hydrogen sulphide at high temperature

Dongjing Liu,Weiguo Zhou,Jiang Wu

The high-temperature H 2 S removal at 500–700 °C was conducted over CuO-CeO 2 /ZSM-5 composites prepared with sol-gel method. 7Cu3Ce/ZSM-5 partially reacting at 500 °C yielded Cu 7 S 4 and Cu 2 S. The major sulphidation products at 600 °C were Ce 2 O 2 S, Cu 2 S, CuS, and S. Sulphidation of 7Cu3Ce/ZSM-5 at 700 °C yielded Ce 2 S 3 , Cu 2 S, Cu 2 S, and S. Sulphidation of 7Cu3Ce/ZSM-5 with 20 % H 2 and 20 % CO generated the same products Ce 2 O 2 S, Cu 2 S, Cu 2 S, and S. Increase in the degree of crystallinity of 7Cu3Ce/ZSM-5 resulted in the decrease of sulphur capacity during the sulphidation and regeneration process. Experimental results showed that the activity of CuO improved by adding Ce; 7Cu3Ce/ZSM-5 performed the optimal sulphiation behaviour at 600 °C with sulphur capacity of 1429 μmol/g (micromoles of sulphur per gram) due to the synergy of CuO and CeO 2 . H 2 repressed sulphur removal, causing the reduction of sulphur capacity from 1429 to 1014 μmol/g. CO had little impact on sulphidation reaction; sulphur capacity only reduced from 1429 to 1221 μmol/g due to the presence of 20 % CO.

Catalytic Conversion of CO2 to Cyclic Carbonates through Multifunctional Zinc-Modified ZSM-5 Zeolite

Qing-Ning Zhao,Qing-Wen Song,Ping Liu,Qian-Xia Zhang,Jun-Hua Gao,Kan Zhang

The production of fine chemicals using CO 2 as C 1 building block through inexpensive heterogeneous catalysts with high efficiency under low pressure is challenging. Herein we propose for the first time the utilization of a multifunctional heterogeneous zinc-modified HZSM-5 (ZnHZSM-5) catalyst for upgrading CO 2 by incorporation into cyclic carbonates from CO 2 and epoxides. Owing to the nice surface properties such as abundant Lewis acid, Brønsted acid and Lewis base sites, large surface area, and plenty of micropores, CO 2 could be concentrated and well activated in ZnHZSM-5 verified by CO 2 -TPD, TG-MS, etc . Meanwhile, the epoxides were also activated through metal center and hydrogen bond. Therefore, the reaction can easily assemble at the catalyst interface and show exceptional performance, affording the aimed products with high yield of up to 99% in the presence of commercial tetra- n -propylammonium bromide (90% in kilogram scale with 0.004 mol% ZnHZSM-5 and 0.015 mol% n Pr 4 NBr).

Supramolecular self-assembly and perfected in vitro/vivo property of 5-fluorouracil and ferulic acid on the strength of double optimized strategy: the first 5-fluorouracial-phenolic acid nutraceutical cocrystal with synergistic antitumor efficacy

Yue-Ming Yu,Yuan-Yuan Niu,Ling-Yang Wang,Yan-Tuan Li,Zhi-Yong Wu,Cui-Wei Yan

For highlighting the predominance of phenolic acid nutraceutical ferulic acid (FR) in regulating the in vivo/vitro performances of anticancer drug 5-fluorouracil (Flu) and strengthening their cooperativity in antitumor effect, thus achieving a major breakthrough in the development of drug-nutraceutical cocrystal with synergistic antitumor action, a cocrystallization strategy of dual optimization is created, in which both the in vivo and vitro natures of Flu are improved by exploiting the FR's excellent physicochemical property. Moreover, Flu's anticancer effects were promoted by exerting the assistant antitumor peculiarity of FR. Such dual optimization of FR for Flu in physicochemical properties and anticancer activities is beneficial for realizing synergistic augmentation effect by taking the benefit of the cooperativeness of Flu and FR in the anticancer ability. Based on this idea, a novel cocrystal of Flu and FR, namely, Flu-FR-H2O, is successfully assembled as the first 5-fluorouracil-nutraceutical cocrystal with synergistic antitumor effect and its explicit structure is resolved. The single-crystal X-ray diffraction demonstrates that Flu and FR have a ratio of 1 : 1 with one equivalent of solvent water in the cocrystal, where one-dimensional hydrogen-bonding helices and FR-Flu hydrogen-bonding pairs, together construct a three-dimensional supramolecular network. By combining experimental evaluation with theoretical analysis, in vitro/vivo pharmaceutical properties are scientifically investigated. Results show that the permeability and aqueous solubility of Flu are respectively elevated by 5.08 and 1.64 folds, which has brought about ameliorated pharmacokinetics, thus providing prolonged retention time and increased oral bioavailability. More interestingly, the cocrystal shows synergistic inhibition ability of Flu and FR against tested tumor cell strains, hence laying the groundwork for reducing the dosage and even the toxic side effects of Flu. As a result of this, the present research not only provides a new strategy for Flu to optimize its physicochemical properties and antitumor activities simultaneously but also offers some opinions for the development of synergistic antitumor pharmaceutical cocrystals.

Poly(2,5-benzimidazole)/sulfonated sepiolite composite membranes with low phosphoric acid doping levels for PEMFC applications in a wide temperature range

Xiaoxiao Zhang,Qingting Liu,Lei Xia,Dongyang Huang,Xudong Fu,Rong Zhang,Shengfei Hu,Feng Zhao,Xiao Li,Xujin Bao

To broaden the operating temperature range of phosphoric acid (PA) doped polybenzimidazole membrane-based proton exchange membrane fuel cells (PEMFCs) toward low temperatures, a novel series of poly(2,5-benzimidazole) (ABPBI)/sulfonated sepiolite (S-Sep) composite membranes (ABPBI/S-Sep) with low PA doping levels (DLs) were prepared via in-situ synthesis. The desirably enhanced mechanical, thermal, and oxidative stabilities of ABPBI/S-Sep composite membranes were achieved by constructing ABPBI chains arranged along the sepiolite (Sep) fibers and acid-base crosslinks formed between S-Sep fibrous particles and ABPBI chains. Benefiting from the richness of high temperature stable bound water and the excellent water absorbability of Sep particles that enable the formation of additive proton conducting paths, the composite membranes retained bounded PA and achieved much higher proton conductivities under both anhydrous and hydrous conditions compared to PA-doped ABPBI membranes. Proton conductivity values above 0.01 S/cm at 40–90 °C/20–98% RH conditions and 90–180 °C/anhydrous conditions as well as peak power density of 0.13 and 0.23 W/cm 2 at 80 and 180 °C with 0% RH, respectively from the ABPBI/2S-Sep composite membrane are more holistic compared to Nafion at low temperatures and polybenzimidazole-based membranes at high temperatures, respectively. The excellent properties of ABPBI/S-Sep composite membranes suggest them as prospective candidates for PEMFCs applications in a wide temperature range.

Selective formation of aromatics through CO2 hydrogenation over HZSM-5 cladded FeK core–shell catalyst

Haripal Singh Malhi,Bantayehu Uba Uge,Lenka Matějová

The selective hydrogenation of CO 2 to produce aromatics presents an intriguing approach for carbon utilization and the formation of high-value chemicals. This study presents a novel core–shell FeK@HZSM-5 catalyst, developed by cladding HZSM-5 zeolite onto a K-promoted Fe oxide core, to enable the direct conversion of CO 2 into aromatics. Under optimum reaction conditions (320 °C, 2.0 MPa, H 2 /CO 2  = 3), the FeK@HZSM-5 catalyst accomplishes 43.2 % selectivity for aromatics at 31.1 % conversion of CO 2 , outperforming the physically mixed FeK-HZSM-5 catalyst (aromatics selectivity: 31.8 %) while keeping CH 4 selectivity below 12 %. Mechanistic investigations reveal that the reaction follows a tandem RWGS-FTS pathway, with olefins serving as crucial intermediates. Robust interactions between Fe and zeolite enhance the stability of active Fe 5 C 2 phases and graphitic carbon, promoting olefin chain growth while inhibiting methanation. The appropriate density of Brønsted acid sites facilitates efficient aromatization, whereas an excess of acidity and increased shell thickness result in over-hydrocracking. The FeK@HZSM-5 catalyst exhibits a notable improvement in CO 2 adsorption capacity, attributed to the occurrence of increased oxygen vacancies and higher surface basicity, which facilitates effective CO 2 activation. The confinement effect of the zeolite shell further modulates intermediate diffusion and water retention. A FeK-to-HZSM-5 wt ratio of 1:2 provides the optimal structural and chemical balance. The catalyst exhibits remarkable stability after 100 h of operation with minimal coke deposition, emphasizing its promise for industrial CO 2 -to-aromatics conversion.

DNA damage protection and 5-lipoxygenase inhibiting activity of areca (Areca catechu L.) inflorescence extracts

W Chen,C Zhang,Y Huang,F Cheng,S Zhao,Y Shen,J Liu

Engineering Single-Atom Sn-doped ZnIn2S4 for Enhanced Aqueous-Phase Selective Photooxidation of 5-Hydroxymethylfurfural

Chen Kun,Wang Zhou,Zhou Xuefei,Ma Tenghao,Zhao Peng,He Yuan,Chen Zhanwei,Zhou Zhihua,Yang Shaowei,Zhang Qiuyu,Zhang Hepeng

ZnIn 2 S 4 -based photocatalysts have attracted considerable attention in biomass valorization owing to their tunable band structures and abundant surface reaction sites. However, the aqueous-phase selective photooxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) remains highly challenging due to the insufficient O 2 activation, substrate mineralization, and competitive coupling side reactions. Herein, a single-atom Sn-doped ZnIn 2 S 4 photocatalyst (Sn-ZIS) was constructed. Systematic characterizations confirm that Sn species are atomically dispersed and incorporated into the ZnIn 2 S 4 lattice through Sn-S coordination. Under aqueous-phase reaction conditions, Sn-ZIS achieves 88.7% HMF conversion, 80.5% DFF selectivity, and 93.3% C equilibrium, higher than those of ZnIn 2 S 4 and many reported aqueous-phase photocatalytic systems. The better performance of Sn-ZIS is mainly attributed to the synergistic regulation of the band structure and local electronic structure induced by Sn incorporation. The optimized band structure moderately weakens the oxidative ability of photogenerated holes, thereby reducing HMF mineralization to CO 2 . While the regulation of the local electronic structure promotes O 2 adsorption and activation to generate superoxide radicals, it simultaneously facilitates DFF desorption from the catalyst surface. Synergy between the two functions drives the selective conversion of HMF into DFF. This work demonstrates the potential of single-atom doping for enhancing aqueous-phase biomass photooxidation and provides a rational strategy for designing efficient ZnIn 2 S 4 -based photocatalysts.

Encapsulation of Pt Nanoparticles in ZSM-5 Zeolite for the Durable Hydrogen-Water Isotope Exchange

Xiaolin Zhou,Jun Chen,Zhen Wang,Yuwen Jiang,Zeping Peng,Yifei Yang

Bifunctional Pt-zeolite catalysts have shown outstanding activity for hydrogen-water isotope exchange due to the highly-efficient synergy between metal and Brønsted acid. However, the aggregation and sintering of Pt particles during this reaction impose the great difficulties for their practical applications. Here, the highly dispersed Pt nanoparticles were embedded into framework or channeled within micropores of ZSM-5 by one-pot hydrothermal synthesis to form the encapsulated catalysts. For comparison, a supported one with Pt species predominantly dewelled on the extra-framework was prepared to interrogate their catalytic durabilities during H 2 -HDO isotope exchange. The similarly catalytic efficacy of metal-acid enables the encapsulated and supported ones to share the same reaction pathway by the protonated water clusters on acid sites to deliver deuteron to reactive ones for the interfacial hydrogen isotope exchange between Pt and water cluster, leading to the measured reaction rate and activation energy to be comparable. During the long-term running, the encapsulated Pt-zeolite catalyst exhibits the superior stability with the ignorable activity loss due to the physical constraint effect to suppress the migration of Pt species. However, the absence of this effect upon the supported one causes the severe sintering and agglomeration of metal species, which greatly deteriorates the catalytic exchange. Graphical Pt nanoparticles were hydrothermally introduced within ZSM-5 framework for the liquid-phase hydrogen-water isotope exchange. This encapsulated structure exhibited the exceptional durability in long-term running, due to the inhibition of Pt species migration by the physical confinement effect of rigid framework.

The neuronal ALAS2/5-ala axis mitigates chemotherapy-induced neurotoxicity via the BACH1/NRF2 pathway

Wen-yuan Zhang,Qian-qian Wei,Tao Zhang,Chunmei Geng,Hai-yan Wu,Chang-shui Wang,Jing Chen,Lei Feng,Pei Jiang

Background and Purpose Despite breakthroughs in immunotherapy and targeted therapies, chemotherapy remains indispensable in oncology. Experimental Approach This study seeks to pinpoint key pathways in doxorubicin (DOX)-treated mouse hippocampus, utilising comprehensive transcriptomic and metabolomic analyses, and validating the mechanisms in vitro and in vivo. Key Results Our multi-omics investigation revealed that sustained DOX exposure induced significant down-regulation of 5-aminolevulinate synthase 2 (ALAS2) and its catalytic product 5-aminolevulinic acid (5-ALA) in the hippocampal region. ALAS2 deficiency was specific to hippocampal neurons, which were more sensitive to oxidative damage than astrocytes or microglia. In vivo and in vitro studies demonstrated that 5-ALA administration or ALAS2 overexpression protected the brain from DOX-induced neurotoxicity. ALAS2 catalyses the condensation of glycine and succinyl-CoA to form 5-ALA, the key precursor of haem. Beyond its role in erythropoiesis, haem is a metabolite that modulates cellular redox homeostasis through interactions with the BACH1 (BTB and CNC homology 1)/NRF2 (nuclear factor erythroid 2 like 2) pathway. We found that DOX suppressed the ALAS2/5-ALA axis, thereby enhancing BACH1 stability. This stabilised BACH1 competes with NRF2 for binding to antioxidant response elements (AREs) in target gene promoters. Conversely, reinforcing the ALAS2/5-ALA axis elevated intracellular haem levels, promoting BACH1 degradation and enhancing NRF2 activity. Using a zebrafish model, we further highlighted the antioxidant and neuroprotective role of 5-ALA against DOX-induced neurotoxicity. Conclusions and Implications In conclusion, this study elucidates a novel endogenous neuroprotective mechanism wherein the ALAS2/5-ALA axis modulates the BACH1/NRF2 pathway. 5-ALA shows promise for repurposing to mitigate chemotherapy-associated neurotoxicity. Graphical

Scalable Cu-CoOx Electrode for 5-Hydroxymethylfurfural Electrooxidation to 2,5-Furandicarboxylic Acid at >100 A

Ren Yue,Miao Yuhang,Ren Qinghui,Wang Shen,Zhang Liyi,Li Ling,Pan Dengke,Zhou Hua,Shao Mingfei

Biomass conversion to building blocks powered by renewable electricity offers a promising route toward low-carbon plastics, as exemplified by the electrooxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). However, this field is limited by a scalable electrocatalyst that can be operated at a large current. Here, we report a facile and scalable Cu-Co bimetal oxide (Cu-CoO x ) electrocatalyst for efficient HMF oxidation. Comprehensive studies reveal that Cu promotes hydroxyl adsorption to form Co(OH) 2 and converts to CoO x (OH) y via electrooxidation. The Cu-CoO x catalyst was evaluated in a continuous-flow reactor with 200 cm 2 of electrode area, achieving high Faradaic efficiency (92.49%) and selectivity (ca. 89%) toward FDCA at large operation currents (40–200 A). Moreover, this reactor was operated at 100 A for more than 100 h, reaching high single-pass conversion efficiency (96.5%) and FDCA selectivity (95.5%). This work provides a foundation for the development of stable and large-area electrodes to enable scalable FDCA electrosynthesis.

Direct Hydrodeoxygenation of Epoxy Resin into Aviation-Fuel-Range Cycloalkanes over Ni/HZSM-5 Catalysts

Yutong Wang,Hongxu Liu,Junhao Guo,Xi Chen,Yajie Tian,Kangjun Wang

The upcycling of thermoset epoxy resins remains challenging due to their highly cross-linked and chemically inert network structures. Herein, an efficient catalytic hydrodeoxygenation (HDO) route is developed for the direct conversion of bisphenol A-based epoxy resin into aviation-fuel-range cycloalkanes over Ni/HZSM-5 catalyst. Under mild conditions (220 °C, 4 MPa H2), the optimized 15Ni/HZSM-5(360) catalyst achieves a total cycloalkane yield of 92.4%, with the C15 dicycloalkane propane-2,2-diyldicyclohexane accounting for 78.5%. Systematic tuning of Ni loading and support acidity reveals that a balanced interplay between Ni hydrogenation sites and moderated Brønsted acidity is essential for promoting selective C–O bond scission while suppressing excessive C–C bond scission. Time-dependent product analysis suggests C15 cycloalcohols as key intermediates, elucidating a stepwise depolymerization and HDO pathway. Combined techno-economic analysis and life-cycle assessment further demonstrate the economic competitiveness and environmental viability of this catalytic strategy for epoxy resin waste valorization.

5-Bromocytidine protects against hyperuricemia-induced renal injury by suppressing TLR4/NF-κB-mediated inflammation

Menghan Wang,Liang Han,Dong Tian,Xinrui Meng,Zhanghui Guan,Zhuozhou Hu,Jia Kang,Xiaoshan Gao,Yixuan Zhang,Youquan Gu,Xiaohua Liu,Xinping Chen

Hyperuricemia (HUA), a prevalent metabolic disorder, is an independent risk factor for chronic kidney disease (CKD). Elevated serum uric acid (UA) level leads to renal UA deposition, causing kidney inflammation, impairing renal function, and accelerating HUA progression. In this study, an inflammation model in RAW264.7 cells induced by monosodium urate (MSU) was established to screen for compounds resistant to MSU-induced inflammation. Fortunately, 5-bromocytidine, a nucleic acid analogue, demonstrated potent anti-inflammatory activity in MSU-treated RAW264.7 cells and exhibited excellent therapeutic effects in HUA rats by reducing serum UA, creatinine (CRE) and blood urea nitrogen (BUN) amounts. Furthermore, we found that 5-bromocytidine blocked the activation of TLR4/NF-κB signaling pathway which mediated inflammation, and downregulated the expression of IL-1β and NLRP3. In summary, 5-bromocytidine may ameliorate HUA by suppressing the renal TLR4/NF-κB signaling pathway, suggesting a new candidate compound for HUA therapy.