Catalysts
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2018
·Vol. 8
·期 2
·82
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IF 3.465
Yadong Bi,Xiaojuan Lei,Guihua Xu,Hui Chen,Jianli Hu
The hierarchical HZSM-5 and Hβ zeolites were prepared by alkaline post-treatment methods adopting Na2CO3, TMAOH/NaOH mixture, and NaOH as desilication sources, respectively. More mesopores are produced over two kinds of zeolites, while the micropores portion is well preserved. The mesopores formed in hierarchical Hβ zeolites were directly related to the basicity of the alkaline solution, indicating that Hβ zeolite is more sensitive to the alkaline post-treatment. The hierarchical HZSM-5 and Hβ zeolites are more active than the parent one for catalytic fast pyrolysis (CFP) of Kraft lignin. Hierarchical zeolites retained the function of acid catalysis, while additionally creating larger mesopores to ensure the entry of bulkier reactant molecules. The increase of the condensable volatiles yield can be attributed to the improvement of the mass transfer performance, which correlates well with the change of mesoporous surface area. In particular, the condensable volatiles yield for the optimized hierarchical Hβ reached approximately two times that of the parent Hβ zeolites. In contrast to the parent HZSM-5, the optimized hierarchical HZSM-5 zeolite significantly reduced the selectivity of oxygenates from 27.2% to 3.3%.Keywords:catalytic fast pyrolysis;Kraft lignin;hierarchical zeolites;HZSM-5;Hβ
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CATALYSIS TODAY
·
2018
·
IF 4.667
Yuexin Peng,Ling Zhang,Yiwen Jiang,Shichao Han,Qiuyan Zhu,Xiangju Meng,Feng-Shou Xiao
Catalytic combustion is considered as an efficient and economic technology to remove VOCs, and Al-ZSM-5 zeolite supported palladium catalysts (Pd/Al-ZSM-5) with good performances in this kind of reactions have been reported. In this work, it is found that Fe-ZSM-5 supported palladium catalyst (Pd/Fe-ZSM-5) exhibit higher catalytic activity in toluene combustion than the Pd/Al-ZSM-5, which is strongly related to more Pd 0 active species and higher concentration of absorbed oxygen species of Pd/Fe-ZSM-5 than those of Pd/Al-ZSM-5. More importantly, Pd/Fe-ZSM-5 has a good catalyst life and water-resistant ability, which should be potentially significant for practical applications in environment protection.
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MATERIALS CHEMISTRY AND PHYSICS
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2017
·
IF 2.084
Yisong Wang,Tao Du,Ziyang Qiu,Yanli Song,Shuai Che,Xin Fang
Mesoporous ZSM-5 zeolite as the adsorbent supporting material was synthesized from rice husk ash (RHA), and then impregnated with polyethylenimine (PEI) for amine functional modification. A series of adsorbents (ZSM-5-PEI-X) with different PEI loading ratios were characterized by XRD , FTIR , TGA/DTG, nitrogen adsorption-desorption, SEM and EDX techniques. The measurement of the adsorption capacity at different temperatures was indicated that ZSM-5-PEI-30 had the highest adsorption capacity at 120 °C (1.96 mmol/g). The experimental data were fitted by adsorption kinetic models and isotherm models, indicated that fractional-order model and the Dual-site langmuir model can be used to describe the adsorption mechanism and predict the adsorption performance. The high CO 2 adsorption selectivity and regeneration stability suggested that this adsorbent is a potential candidate in the adsorption and separation of CO 2 in industrial flue gas .
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PETROLEUM SCIENCE AND TECHNOLOGY
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2017
·
IF 0.655
Lanyu Xing,Zhenhao Wei,Zhenhao Wen,Xuedong Zhu
Hierarchical and conventional ZSM-5 zeolites were synthesized through steam-assisted crystallization approach using acid-treatment kaolin clay as the silica and aluminium sources. The samples were characterized by XRD, SEM, NH3-TPD, N2-physisorption and TG techniques. The results showed that hierarchical ZSM-5 had rich mesopores and bigger specific surface. In conversion of methanol to aromatics, hierarchical and conventional ZSM-5 zeolites showed higher selectivity for aromatics compared with commercial ZSM-5. Under the conditions of 450 °C, 0.15 MPa, the synthesized hierarchical ZSM-5 showed longest lifetime of 380 h, which was 2 and 6 times than those of conventional and commercial ZSM-5, respectively.
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JOURNAL OF MEMBRANE SCIENCE
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2017
·
IF 6.035
Li Peng,Xiaohan Xu,Xun Yao,Hua Liu,Xuehong Gu
A series of novel hierarchical ZSM-5 zeolite membranes with tunable mesopore sizes have been prepared successfully by using amphiphilic organosilane 3-[(trimethoxysilyl) propyl]octyldimethyl-ammonium chloride (TPOAC) as the mesogenous template and part of the Si source. The effects of several synthesis parameters, such as the TPOAC/SiO 2 ratio, synthesis temperature and crystallization time, on the microstructures and rejection performance of the hierarchical ZSM-5 zeolite membranes were systematically investigated. Multiple techniques, such as XRD , SEM, N 2 adsorption techniques, TEM, IR, 13 C MAS NMR and 29 Si MAS NMR were employed for the characterizations. The filtration of dextran in water shows that the membranes have molecular weight cutoff (MWCO) ranging from 9500 to 943,000, corresponding to the molecular size in the range of 4.5–37 nm. The sharp increase in the rejection of dextran with the increase of molecular weight indicated narrow pore size distribution of the membrane. These results show that the hierarchical mesoporous ZSM-5 zeolite membranes have a great potential for ultrafiltration with high performance.
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CHEMISTRY-A EUROPEAN JOURNAL
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2017
·Vol. 23
·期 62
·15721-15728
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IF 5.317
Yuanyuan Hu,Dong Xie,Yang Wu,Nangui Lin,Aixin Song,Jingcheng Hao
Graphical Stacking gels : Factors affecting the self-assembly of supramolecular hydrogels composed of combining 5′-adenosine monophosphate and Ag + are discussed (see figure). The gelation capability was enhanced by increasing the concentration of Ag + or decreasing the pH. The gels are very sensitive to light and have potential applications as photosensitive materials. Supramolecular hydrogels obtained by combining 5′-adenosine monophosphate (AMP) with Ag + were fabricated in this work. Their gelation capability was enhanced by increasing the concentration of Ag + or decreasing the pH. The gels are very sensitive to light, which endows them with potential applications as visible-light photosensitive materials. Coordination between the nucleobase of AMP and Ag + , as well as π–π stacking of nucleobases, are considered to be the main driving forces for self-assembly. The hydrogels successfully achieved the encapsulation and enrichment of biomolecules. Hydrogen bonding between the amino group of guest molecules and silver nanoparticles along the nanofibers drives the enrichment and is considered to be a crucial interaction.
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PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
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2024
·Vol. 25
·期 18
·10188
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IF 4.9
Peng Zhao,Zifu Wang,Shimei Liao,Yangxin Liao,Shijun Hu,Jianchun Qin,Donghua Zhang,Xiaohui Yan
Salvia leucanthais a perennial herb of the genusSalviain the family Labiatae, which has a wide range of biological activities, mainly including inhibition of acetylcholinesterase, antibacterial, and anti-inflammatory activity. To explore the protective effects and mechanism of action ofS. leucanthaon Alzheimer’s disease (AD), the anti-AD activity of SLE (extracts ofS. leucantha) was determined by using a transgenicCaenorhabditis elegans(C. elegans) model (CL4176). Analyses included paralysis assay, phenotypic experiments, transcriptome sequencing, RNA interference (RNAi), heat shock assays, and gas chromatography-mass spectrometry (GC-MS). SLPE (S. leucanthapetroleum ether extract) could significantly delay CL4176 paralysis and extend the longevity ofC. elegansN2 without harmful effects. A total of 927 genes were significantly changed by SLPE treatment inC. elegans,mainly involving longevity regulatory pathways—nematodes, drug metabolism—cytochrome P450, and glutathione metabolic pathways. RNAi showed that SLPE exerted its anti-AD activity through up-regulation of the genegst-5; the most abundant compound in SLPE analyzed by GC-MS was 2,4-Di-tert-butylphenol (2,4-DTBP), and the compound delayed nematode paralysis. The present study suggests that active components inS. leucanthamay serve as new-type anti-AD candidates and provide some insights into their biological functions.
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Molbank
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2024
·Vol. 2024
·期 2
·M1818
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IF 0.6
Zhongwei Wang,Luxiao Zhou,Peng He,Yukun Qin
This study presents a novel approach in the realm of catalytic organic synthesis by integrating biomass catalytic conversion with organic synthesis techniques. UtilizingN-acetylglucosamine as the primary feedstock, the first phase of the research involves its catalytic transformation into 5-hydroxymethylfurfural (HMF). The subsequent phase employs a condensation reaction between HMF and 3,3-Dimethyl-2-butanone to synthesize a new compound, (E)-1-(5-(hydroxymethyl) furan-2-yl)-4,4-dimethylpent-1-en-3-one. This two-step process not only demonstrates the feasibility of converting biomass into valuable chemical precursors but also exemplifies the synthesis of novel compounds through green chemistry principles. The successful execution of this methodology offers fresh insights and opens new avenues for advancements in catalytic organic synthesis, emphasizing sustainability and efficiency.
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RSC Advances
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2017
·Vol. 7
·期 27
·16311-16318
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IF 3.108
Yue Yang,Qiying Liu,Dan Li,Jin Tan,Qi Zhang,Chenguang Wang,Longlong Ma
Selective hydrogenation of 5-hydroxymethylfurfural (HMF) has potential application in high quality biofuels. Herein, the catalytic hydrodeoxygenation (HDO) of HMF to 2,5-dimethylfuran (DMF) was investigated using bi-functional Ru–MoOx/C catalyst prepared by initial wetness impregnation. The high dispersion and electronic transfer between Ru and MoOx were demonstrated by a series of characterization techniques. During this HDO process, the synergy effect between metallic Ru and acidic MoOx species in the Ru–MoOx/C catalyst plays an essential role in obtaining maximized target product DMF (79.4%) via effective aldehyde group hydrogenation by Ru followed by dehydration over MoOx. This work also elucidated that DMF production proceeded through two distinct pathways: the 2,5-hydroxymethyl furan intermediate was preferable by the aldehyde group hydrogenation of HMF over the Ru–MoOx/C catalyst. Over MoOx/C catalyst, comparatively, 5-methyl furfural was the key intermediate by direct hydrogenolysis of the hydroxyl group in HMF. This kind of catalyst is stable for the first two runs by maintaining the target product yield. After the third run, the catalyst showed deactivation gradually but could be almost completely recovered after regeneration by H2 reduction.
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FUEL PROCESSING TECHNOLOGY
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2016
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IF 3.847
Haian Xia,Siquan Xu,Xiaopei Yan,Songlin Zuo
It is of great significance to explore and develop a cost-effective and environmentally friendly way to covert cellulosic materials into 5-hydroxymethylfurfural (5-HMF). An inexpensive FePO 4 catalyst, which is insoluble at room temperature but can be partially dissolved and behaves as homogeneous catalyst at elevated temperatures, was used to directly convert cellulose into 5-HMF. The effect of various reaction conditions including reaction temperature, reaction time, cellulose concentration and catalyst amount on the conversion of cellulose and 5-HMF yield was investigated. A 5-HMF yield up to 49.5 mol% was achieved at 160 °C for 60 min with the FePO 4 catalyst, which is comparable to the highest yield of 5-HMF obtained in ionic liquid or homogeneous catalysis reaction systems. Moreover, this unique catalyst is readily separated from the aqueous solution via precipitation after cooling to room temperature since it is insoluble at room temperature. The catalyst can be used over five successive cycles although the amorphous FePO 4 underwent the structural transformation from an amorphous phase into a new crystalline form of FePO 4 , evidenced by XRD, IR, and visible Raman spectroscopic results. The soluble iron species, such as Fe 3 + species, act as Lewis acid sites catalyzing isomerization of glucose to fructose followed by the dehydration of fructose into 5-HMF catalyzed by H + ions.
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AICHE JOURNAL
·
2016
·Vol. 62
·期 12
·4403-4417
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IF 2.98
Ye Su,Ganggang Chang,Zhiguo Zhang,Huabin Xing,Baogen Su,Qiwei Yang,Qilong Ren,Yiwen Yang,Zongbi Bao
Glucose conversion to 5-hydroxymethylfurfural (HMF) generally undergoes catalytic isomerization reaction by Lewis acids followed by the catalytical dehydration to HMF with Brönsted acid. In this work, a sulfonic acid functionalized metal-organic framework MIL-101(Cr)-SO 3 H containing both Lewis acid and Brönsted acid sites, was examined as the catalyst for γ-valerolactone-mediated cascade reaction of glucose dehydration into HMF. Under the optimal reaction conditions, the batch heterogeneous reaction gave a HMF yield of 44.9% and selectivity of 45.8%. Reaction kinetics suggested that the glucose isomerization in GVL with 10 wt % water follows the second-order kinetics with an apparent activation energy of 100.9 kJ mol −1 . Continuous reaction in the fixed-bed reactor showed that the catalyst is highly stable and able to provide a steady HMF yield. This work presents a sustainable and green process for catalytic dehydration of biomass-derived carbohydrate to HMF with a bifunctional metal-organic framework. © 2016 American Institute of Chemical Engineers AIChE J , 62: 4403–4417, 2016
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CHINESE CHEMICAL LETTERS
·
2016
·
IF 1.947
Yu-Tao Zheng,Teng-Teng Zhang,Pei-Yi Wang,Zhi-Bing Wu,Lei Zhou,Yi-Qiang Ye,Xiang Zhou,Ming He,Song Yang
By introducing the pyrazole moiety into the 5-position of 1,3,4-oxadiazole, a series of novel 2-(thioether/sulfone)-5-pyrazolyl-1,3,4-oxadiazole derivatives were synthesized. Preliminary bioassays suggested that target compounds exhibited appreciable activity against pathogenic bacteria Xanthomonas oryzae pv. oryzae ( Xoo ) and five phytopathogenic fungi in vitro . Among them, the half-maximal effective concentration (EC 50 ) values of 6c , 7a , 7b and 7c against Xoo were within 16.6 μg/mL and 65.7 μg/mL, which were better than those of commercial agricultural antibacterial bismerthiazol (92.6 μg/mL) and thiodiazole copper (121.8 μg/mL). While compounds 7a , 7b , and 7c exerted comprehensive antifungal activity toward five plant fungi, which were comparable with that of hymexazol. The results demonstrated that this kind of compounds can be further studied and developed as promising antifungal and antibacterial agents.
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