查找使用阿拉丁产品的科研文献

Encapsulation of ultra-small Cu–Fe into ZSM-5 zeolites for NH3-SCR with broad reaction-temperature ranges

En-Hui Yuan,Meng Li,Ming-Hui Yang,Xiaosheng Huang,Kun Zhang,Weiliang Han,Zhicheng Tang,Zhong-Wen Liu

A direct hydrothermal synthesis strategy is developed to prepare the Cu–Fe-ZSM-5 zeolites by using the ethylenediaminetetraacetic acid disodium dihydrate (EDTA-2Na·2H 2 O) chelated Cu 2+ and Fe 3+ precursors as metal sources. During the crystallization, the metal chelates were spontaneously embedded into the ZSM-5 crystals and subsequently transformed to the zeolites encapsulated copper and iron species after removing the chelating agent via the high-temperature calcination . Rigorous characterizations indicate that the resulted Cu 2+ /Cu + and Fe 3+ /Fe 2+ species are formed ultra-small nano-composites with an average diameter of ∼2.2 nm and highly dispersed in the ZSM-5 zeolite crystals. The acidity of the ZSM-5 zeolites is subtly modulated by the encapsulated Cu–Fe nano-composite. As expected, the as-prepared Cu–Fe-ZSM-5 exhibits outstanding catalytic performance for the selective catalytic reduction of NO x with ammonia (NH 3 -SCR) in the broad reaction temperature ranges of 220–480 °C, which is much better than the Cu–Fe/ZSM-5 prepared with the conventional wetness impregnation method. Furthermore, the resultant zeolites show high stability and good tolerance to H 2 O and SO 2 , and it is very competitive for practical application to eliminate NO x . The developed one-pot hydrothermal synthesis route by using EDTA-2Na·2H 2 O as chelating agent is very convenient and easily reproducible, providing a general guideline to design and fabricate the superior transition metal modified zeolite catalysts for NH 3 -SCR and the related reactions.

Catalytic Oxidation of 5-Hydroxymethylfurfural into 2,5-Diformylfuran Over Vanadyl and Cupric Immobilized on Amino-Functionalized MCM-41

Liu Chenlu,Liao Longfei,Li Zengyong,Liu Ying,Wu Shubin,Zhuang Junping

Mesoporous MCM-41 was amino-functionalized to immobilize cupric (Cu2+) and vanadyl (VO2+) for preparing MCM–NH2–Cu2+ and MCM–NH2–VO2+ co-catalysts. The as-prepared two catalysts had been characterized by XRD, N2 adsorption–desorption, FT-IR, XPS and TEM. The catalytic performance of MCM–NH2–VO2+ in HMF oxidation could be significantly promoted by using MCM–NH2–Cu2+ as the co-catalysts. Several critical reaction parameters had been investigated, and it indicated that the highest conversion of 5-hydroxymethylfurfural (HMF) obtained was 98.1% at 110 °C in toluene with an optimal 2,5-diformylfuran (DFF) yield of 61.2%. Particularly, the MCM–NH2–Cu2+ and MCM–NH2–VO2+ catalyst exhibited great stability and can be reused and showed no significant loss of their catalytic activities.

Equilibrium Phase Relationships of CaO-SiO2-TiO2 System with 5 wt% Cr2O3 Addition for Titania-Bearing Slag Recycling

Lv Ningning,Qiu Yuchao,Hu Yiming,Shi Hangkai,Shi Junjie,Ding Xiang,Li Haolun

It has been proved that Cr 2 O 3 is favorable to promote the crystallization of perovskite in the Selective Crystallization and Phase Separation (SCPS) process. However, the related thermodynamic data of equilibrium phase relations was quite limited. In the present work, the equilibrium phase relations of CaO-SiO 2 -TiO 2 system with the addition of 5 wt% Cr 2 O 3 were experimentally carried out using the high temperature equilibration-quenching technique followed by X-Ray Diffraction (XRD), Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM–EDS), as well as thermodynamic calculation. More attention has been focused on the influence of 5 wt% Cr 2 O 3 addition on the liquid-perovskite two-phase coexisting region. The results indicated that the crystallization of perovskite was promoted by Cr 2 O 3 addition by expanding the primary phase of perovskite toward higher SiO 2 areas. Meanwhile, distinct discrepancies were found when the present experimental results were compared with the data from the literature and the isotherms calculated by FactSage, indicating that the present results are not only meaningful for the improvement of the SCPS process, but also important for the optimization of titania related oxide thermodynamic database. Graphical Abstract

Coordination of Acidic Deep Eutectic Solvent–Chromium Trichloride Catalytic System for Efficient Synthesis of Fructose to 5-Hydroxymethylfurfual

Qingyin Li,Kai Sun,Yuewen Shao,Shu Zhang,Zifeng Yan,Lijun Zhang,Qing Liu,Yi Wang,Xun Hu

Development of an eco-friendly and effective reaction system for production of platform chemicals like 5-hydroxymethylfurfural (HMF) has always been a hot topic in biorefineries. In this study, the acidic deep eutectic solvents (DESs) coupled with chromium chloride (CrCl3) have been developed for effective conversion of fructose to HMF under a microwave-assisted manner. The acidic DES was composed of an organic acid and choline chloride (ChCl). Among the organic acids screened, the ChCl–HCOOH system was found to be the most effective medium for the HMF production, which was attributed to the smaller molecular structure and stronger acidity. Such an observation was also consistent with the larger interaction potential energy between fructose and ChCl–HCOOH obtained from the Monte Carlo simulation. In addition, a synergistic effect achieved from the ChCl–HCOOH/CrCl3 mixture played a vital role on the formation of HMF. The ChCl–HCOOH/CrCl3 system could be reutilized without remarkable change in HMF yield, indicating the advantages of ease of recovery and high catalytic stability.

Efficient aerobic oxidation of biomass-derived 5-hydroxymethylfurfural to 2,5-diformylfuran catalyzed by magnetic nanoparticle supported manganese oxide

Bing Liu,Zehui Zhang,Kangle Lv,Kejian Deng,Hongmin Duan

Magnetic Fe 3 O 4 supported Mn 3 O 4 nanoparticles (Fe 3 O 4 /Mn 3 O 4 ) were prepared by the solvent thermal method, and its structure was characterized by XRD, XPS, TEM, and FT-IR technologies. The resulting Fe 3 O 4 /Mn 3 O 4 nanoparticles could be used as an excellent heterogeneous catalyst for the aerobic oxidation of the biomass-derived model molecule 5-hydroxymethylfurfural into 2,5-diformylfuran (DFF) under benign reaction conditions. Some important reaction parameters such as reaction temperature, catalyst amount, solvent, oxidant, and oxygen pressure were explored and high DFF yield of 82.1% with HMF conversion of 100% were obtained in DMF under optimal reaction conditions. More importantly, the catalyst could be readily separated from the reaction mixture by a permanent magnet, and recycled up to 6 times without the significant loss of its catalytic activity.

Shaoyao Decoction reduced T lymphocyte activation by regulating of intestinal flora and 5-hydroxytryptamine metabolism in ulcerative colitis

Zhen Jianhua,Li Yini,Zhang Yunan,Zhou Yali,Zhao Lu,Huang Guangrui,Xu Anlong

Background Shaoyao Decoction (SYD) is a widely recognized herbal formula utilized in traditional Chinese medicine for the treatment of diarrhea. Although it has demonstrated significant effectiveness in clinical practice for treating ulcerative colitis, the precise mechanisms by which it operates remain largely elusive. Methods The active ingredients of SYD were obtained by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS), which were used to explore the potential pharmacological mechanism based on TCMSP (Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform) and PANTHER (Protein Analysis Through Evolutionary Relationships) classification system. In a mouse model of dextran sulfate sodium (DSS)-induced colitis, mRNA sequencing, 16S rDNA sequencing and targeted metabolomics techniques were used to elucidate the mechanisms of SYD, and immunohistochemistry, immunofluorescence, enzyme linked immunosorbent assay, real time quantitative polymerase chain reaction and western blot were used to test the key targets. In addition, QGP-1 and H9 cells were performed to validate the discoveries from the animal experiments. Results In the mouse model of DSS-induced colitis, SYD effectively alleviated symptoms such as bloody stool, tissue damage, inflammation, intestinal flora dysbiosis and abnormal gene expression. Analyses of both differential expressed genes in colonic tissue and predicted 16S rDNA genes, as well as the analyses of targeted genes from TCMSP based on the active ingredients in UPLC-MS/MS of SYD, uncovered the enrichment of pathways involved in the biosynthesis and degredation of 5-hydroxytryptamine (5-HT). Interestingly, SYD suppressed the relative abundance of key genes in 5-HT synthesis, Tph1(Tryptophan hydroxylase 1) and Ddc (Dopa decarboxylase), in faeces from DSS-induced mice, leading to a reduction in the concentration of fecal 5-HT. Moreover, SYD augmented the production of butyric acid. Subsequently, increasing butyric acid influenced the metabolism of 5-HT in the organism through G protein-coupled receptor 43 by impeding its synthesis, facilitating its transport and degredation. These findings were additionally corroborated in a model utilizing enterochromaffin cell (QGP-1 cells). Furthermore, reduced levels of 5-HT hindered the activation of T lymphocytes (H9 cells) via the PKC (Protein kinase C) and NF-κB (Nuclear factor kappa-B) signaling pathways, by means of HTR1A (5-HT receptor 1A) and HTR3 (5-HT receptor 3). Additionally, diminished secretion of 5-HT resulted in reduced secretion of associated cytokines, thereby alleviating inflammation in the colon. Conclusion Through modulation of T lymphocyte activation mediated by 5-HT metabolism in the local colon via the intestinal flora and its metabolite, SYD effectively mitigated colonic inflammation in DSS-induced mice.

Phase tuning of ZrO2 supported cobalt catalysts for hydrodeoxygenation of 5-hydroxymethylfurfural to 2,5-dimethylfuran under mild conditions

Tianci Xiao,Xiaohao Liu,Guangyue Xu,Ying Zhang

Crystal structure of catalyst support has great influence on its surface and electronic properties. Thus, tuning the crystal phase may adjust the catalytic activity. Herein, we prepared a series of monoclinic, tetragonal and mixed phase of Co/ZrO 2 catalysts, denoted as Co/m-ZrO 2 , Co/t-ZrO 2 and Co/Mix-ZrO 2 . They showed different hydrogenation and hydrogenolysis activities in conversion of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF). The characterization and catalytic performance indicated that the interaction between cobalt and t-ZrO 2 resulted in cobalt electron-deficiency and higher concentration of Zr(III) species, which contributed to the higher hydrogenation activity of carbonyl on Co/t-ZrO 2 than Co/m-ZrO 2 . While the hydrogenolysis of C OH group showed higher efficiency on Co/m-ZrO 2 , which was determined by the acid concentration on the surface of catalysts. The combination of both high hydrogenation and hydrogenolysis activities in Co/Mix-ZrO 2 achieved the highest yield of DMF (90.7 %) under mild conditions of 130 °C and 1 MPa H 2 .

Acidic Site-Controlled ZSM-5 Catalysts for Fast Molten-Phase Pyrolysis of Plastic Waste with Tunable Product Distribution

Wei Xiong,Ruilong Zhang,Christina H. M. Tsang,Yuehan Jiang,Xinxin Lu,Yuchao Shao,Jun Zhao

The catalytic pyrolysis of plastic waste into fuels has attracted considerable attention due to its potential to address the energy crisis and alleviate public health concerns. However, current catalytic pyrolysis systems for waste plastics still face challenges, such as low efficiency, poor product selectivity, and a lack of monitoring during the pyrolysis process. In this study, highly stable ZSM-5 zeolite catalysts were synthesized with tunable Si/Al ratios for the efficient cracking of high-density polyethylene (HDPE) into oil- and hydrocarbon-rich gases. It was found that a decrease in the Si/Al ratio of the ZSM-5 catalyst enhanced its acidity and cracking efficiency for HDPE, as confirmed through a one-pot melting-catalysis strategy and thermogravimetric analysis. The increased acidity of the ZSM-5 catalyst not only improved the cracking efficiency but also facilitated the regulation of product distribution, offering valuable insights into the design of highly selective catalysts. ZSM-5 (22) exhibited the highest conversion rate, achieving nearly 100% HDPE conversion at 450 °C in 19 min and full conversion at a lower temperature of 350 °C over an extended period, and demonstrated good stability and recyclability. The acidic properties and the aluminum coordination state of the prepared ZSM-5 catalysts were examined with a proposed mechanism for high-density polyethylene (HDPE) cracking based on the acidic sites of ZSM-5. Furthermore, the catalyst demonstrated its efficacy in the pyrolysis of actual plastic waste. These findings highlight the potential of ZSM-5 catalysts for the cracking of plastic waste through the one-pot melting-catalysis strategy, offering valuable insights to further advance dynamic studies of plastic cracking processes.

Hypoxia Alleviation Enhances the Efficacy of 5-Fluorouracil in Hypertrophic Scar Therapy via an Oxygen-Popping Microneedle System

Junzhe Fu,Weijiang Yu,Yixian Mu,Xuedan Qian,Xinyi Li,Ke Sun,Youxiang Wang,Jian Ji

Hypertrophic scars (HS) result from aberrant wound healing, often leading to disfigurement and functional impairment. Hypoxia is a prominent feature of HS; however, its impact on therapeutic efficacy remains unexplored, presenting a potential pathway for advancing HS treatments. Here, hypoxia is identified as a limiting factor in the efficacy of 5-fluorouracil (5-Fu), a widely used clinical drug for HS. At the gene expression level, 5-Fu response genes associated with the mitotic cell cycle, such as BUB1 and SPAG5, fail to be downregulated under hypoxia in human HS fibroblasts, contributing to the altered cytotoxic response. To address this limitation, an oxygen-popping microneedle (MN) system is developed to alleviate hypoxia in HS and enhance 5-Fu-based therapy. Inspired by the gas-release mechanism of Pop Rocks candy, high-pressure oxygen-trapping particles (HOTP) are formulated and integrated into a core–shell MN platform, enabling localized co-delivery of oxygen and 5-Fu. The popping release of oxygen also facilitates 5-Fu penetration into dense HS tissue. In vivo studies provide strong evidence that the MN system effectively mitigates hypoxia, significantly enhancing the therapeutic efficacy of 5-Fu. This research presents an innovative strategy for optimizing HS therapy by alleviating hypoxia, with the potential to inform future advancements in HS treatment.

Catalytic pyrolysis of n-paraffin coexisting with olefin over ZSM-5 based catalysts: Experiments, kinetics, and DFT calculations

Dongyang Liu,Yuen Bai,Dongdong Chen,Nan Zhang,Liang Zhao,Jinsen Gao,Chunming Xu

This study investigates the co-cracking of n-hexane and 1-hexene, utilizing 1-hexene as an olefinic initiator to improve light olefin yields. Experimental investigations, kinetic analyses, and density functional theory calculations (DFT) were used to systematically explore cracking performance, interactions, and mechanisms for co-feeding. Comparied with single feeding of n-hexane, leading to higher light olefin yields (increased from 35.77 wt% to 58.61 wt%) when the olefin content is 20 wt%. Kinetic analysis revealed a shift from protolytic to hydrogen transfer cracking pathway when 1-hexene content exceeded 13.6 wt%, with the maximum cracking rate (13.12 h −1 ) constant at 20 wt% olefin content. DFT calculations showed a lower energy barrier for hydrogen transfer cracking between n-hexane and 1-hexene, compared to n-hexane cracking alone. Therefore, a co-cracking mechanism was proposed, involving paraffin activation through carbocation intermediates generated by olefin, followed by β-cracking to generated light olefins and carbenium ion regeneration, establishing a framework for paraffin-olefin co-conversion.

Boosting ionic conductivity of fluoride electrolytes by polyanion coordination chemistry enabling 5 V-Class all-solid-state batteries

Huaimin Jin,Xingyu Wang,Simeng Zhang,Xiangzhen Zhu,Chong Liu,Junyi Yue,Jie Qu,Bei Wu,Xu Han,Yueyue Wang,Yang Xu,Han Wu,Liyu Zhou,Mingying Zhang,Hao Lai,Shuo Wang,Jiangwen Liang,Xueliang Sun,Xiaona Li

Fluoride solid-state electrolytes (SSEs) offer superior electrochemical stability, making them theoretically ideal for high-voltage all-solid-state batteries (ASSBs), but their low Li + conductivity hinders practical application. Here, we exploit the polyanion coordination strategy to develop a class of fluoride SSEs, Li x Ti(PO 4 ) x /3 F 4 , which exhibits high ionic conductivity and ultrahigh-voltage stability. Especially, Li 1.3 Ti(PO 4 ) 1.3/3 F 4 (1.16 × 10 −5 S cm −1 ) demonstrates a two-order-of-magnitude enhancement in Li + conductivity compared to analogous Li 2 TiF 6 . Combined experimental and theoretical analyses reveal that the high ionic conductivity of Li x Ti(PO 4 ) x /3 F 4 arises from weakened Li + -surrounding interactions and flexible network structures. Attractively, the exceptional ionic conductivity and ultrahigh-voltage stability of Li 1.3 Ti(PO 4 ) 1.3/3 F 4 enable a low-resistance and highly stable electrolyte-electrode interface, contributing to 91.6% capacity retention after 200 cycles for 5 V-class LiNi 0.5 Mn 1.5 O 4 -based ASSBs at 1 C and 30°C. The discoveries in this work open a new avenue for designing high-conductivity fluoride SSEs, paving the way for the application of high-voltage cathodes in high-energy-density ASSBs.

Research on the Effect of 5-Aminoindole on Polymerization Behaviors and Mechanical Properties of Poly(Aldehyde Functional Benzoxazine)

Yi Xu,Zhengbai Li,Nan Yang,Yujia Liu,Qiang He,Wenfeng Yang,Chao Li