CATALYSIS TODAY
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2024
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IF 5.2
Longyu Wang,Na Wang,Suohe Yang,Guangxiang He,Haiyan Liu,Xianghai Meng,Chunming Xu,Zhichang Liu,Haibo Jin
A diverse suite of Zn-SAPO-34 catalysts was synthesized employing three distinct methodologies for the incorporation of zinc species: thermal ion exchange, wet impregnation, and physical mixing. The catalysts were characterized using various analytical techniques including XRD, FT-IR, BET, SEM, XRF, XPS, NH 3 -TPD, and Py-IR, to elucidate the crystal structure, morphology, surface acidity, and the presence of zinc species within the catalysts. The study showed that the method of zinc introduction markedly impacts the physicochemical properties of the catalysts. Different approaches to introducing zinc species significantly influence the acid strength and type on the catalyst surface, with variations in the existing states of zinc across the catalysts. Specifically, zinc species introduced via thermal ion exchange coexist as ZnOH + and ZnO within the catalyst, whereas those from wet impregnation and physical mixing are individually present as either ZnOH + or ZnO. Furthermore, the study examined the catalytic performance of these Zn-SAPO-34 catalysts in the dehydration of fructose to produce 5-hydroxymethylfurfural (HMF). Catalysts prepared via thermal ion exchange exhinited superior performance, achieving an remarkable HMF yield of 94.6 %. Additionally, in situ infrared technology was used to investigate the effect of zinc species introduction on the fructose dehydration process, indicating suggesting that the introduction of zinc species enhances the transformation of fructose molecules.
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Royal Society Open Science
·
2018
·Vol. 5
·期 3
·
IF 2.504
Yi Yang,Huiping Zhang,Ying Yan
Fe2O3-ZSM-5 catalysts (0.6 wt% Fe load) prepared by metal-organic chemical vapour deposition (MOCVD) method were evaluated in the catalytic wet peroxide oxidation (CWPO) of m-cresol in a batch reactor. The catalysts have a good iron dispersion and small iron crystalline size, and exhibit high stability during reaction. In addition, the kinetics of the reaction were studied and the initial oxidation rate equation was given. Catalysts were first characterized by N2 adsorption–desorption isotherms, scanning electronic microscopy, energy-dispersive spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Results show that extra-framework Fe3+ species (presenting in the form of Fe2O3) are successfully loaded on ZSM-5 supports by MOCVD method. Performances of catalysts were tested and effects of different temperature, stirring rate, catalyst amount on hydrogen peroxide, m-cresol, total organic carbon (TOC) conversion and Fe leaching concentration were studied. Results reveal that catalytic activity increased with higher temperature, faster stirring rate and larger catalyst amount. In all circumstances, m-cresol conversion could reach 99% in 0.5–2.5 h, and the highest TOC removal (80.5%) is obtained after 3 h under conditions of 60°C, 400 r.p.m. and catalyst amount of 2.5 g l−1. The iron-leaching concentrations are less than 1.1 mg l−1 under all conditions. The initial oxidation rate equation −rA0=7.2×1011e−81300/RTCA is obtained for m-cresol degradation with Fe2O3-ZSM-5 catalysts.
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PubMed
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BIOMASS & BIOENERGY
·
2017
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IF 3.219
Haian Xia,Hong Hu,Siquan Xu,Kehao Xiao,Songlin Zuo
A series of Fe/β zeolite catalysts with various Fe/Al ratios were prepared by liquid ion-exchanged method and were characterized by N 2 adsorption, XRD , UV–Vis DRS, EPR , NH 3 -TPD, and FTIR of pyridine adsorption techniques. The catalysts were used to catalyze the transformation of glucose into 5-hydorxymethyfural (HMF) in a biphasic reaction system under mild reaction conditions. The Fe/β catalysts with Lewis acidic Fe sites is able to effectively improve the HMF yield compared to H-β zeolite under identical reaction conditions, which is ascribed to the enhanced isomerization activity of glucose-to-fructose by Lewis acidic Fe species. Moreover, the Fe/Al ratio had a remarkable impact on the conversion of glucose and the yield of HMF, indicating that the synergetic effect of Lewis and Brønsted acid sites is critical to achieving high HMF yield. Under optimal reaction conditions, Fe/β-0.06 catalyst afforded 61% HMF yield at glucose conversion of 95% after the reaction of 90 min at 120 °C, which is one of the most effective catalysts for the conversion of glucose into HMF in a biphasic medium up to now. Furthermore, extra-framework isolated Fe species bound to the framework Al sites, are most likely the active sites for the isomerization of glucose-to-fructose in the conversion of glucose. The catalysts were very stable and could be reused at least five runs without significant loss in the catalytic activity .
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JOURNAL OF POROUS MATERIALS
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2018
·Vol. 25
·期 6
·1587-1595
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IF 1.858
Shen Yu,Wang Fumin,Liu Wei,Zhang Xubin
A series of Fe 3+ containing catalysts were synthesized using ion-exchange technique over hierarchically porous ZSM-5 (M-ZSM-5) and micro-mesoporous composite ZSM-5/MCM-41 (ZSM-5/MCM-41), respectively. The prepared catalysts were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, N 2 adsorption–desorption, UV–Vis spectroscopy, temperature programmed reduction and inductively coupled plasma-optical emission spectroscopy. The characterization results exhibit that the hierarchically porous ZSM-5 was synthesized with intracrystalline mesopores, while the micro-mesoporous composite ZSM-5/MCM-41 was prepared with the well-ordered mesopores. Furthermore, the results also prove that the existence of iron in the catalysts was mainly presented in the form of Fe 3+ ions. Catalytic performances of the samples for phenol hydroxylation were compared by using H 2 O 2 as oxidant. Under the optimized conditions, Fe 3+ ion-exchanged M-ZSM-5 (Fe-M-ZSM-5) shows that a phenol conversion of 42.3% obtained with 92.5% selectivity to dihydroxybenzenes, whereas Fe 3+ ion-exchanged ZSM-5/MCM-41 (Fe-ZSM-5/MCM-41) give 46.2% phenol conversion and 90.1% dihydroxybenzenes selectivity, which are all better than most reported results. The recyclability tests show that Fe-ZSM-5/MCM-41 with ordered mesoporous structure and bigger surface area has better anti-deactivation performance than Fe-M-ZSM-5. The excellent catalytic performances were due to the improved diffusion performance with newly created mesopores and the highly active Fe 3+ species obtained by ion-exchange technique.
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BIORESOURCE TECHNOLOGY
·
2018
·
IF 5.807
Zihao Zhang,Hao Cheng,Hao Chen,Kequan Chen,Xiuyang Lu,Pingkai Ouyang,Jie Fu
Modified H-type ZSM-5 (HZSM-5) catalysts were prepared using hexadecyl trimethyl ammonium bromide (CTAB) as mesopore templates to enhance the activity for the catalytic fast pyrolysis of rice straw for aromatics compounds. A certain quantity of CTAB added into the HZSM-5 (HZ) forming hierarchical structure exhibited an improvement in the yield of the aromatics and a decrease in the yield of coke in comparison with that of bare HZ. In contrast, excessive CTAB addition resulted in a decrease in aromatic yield and an increase in coke yield. The effects of crystallinity, textural properties, morphological structure and acidity distribution on the production of aromatic compounds were measured by XRD, BET, TEM and NH 3 -TPD. The good crystallinity, small amount of mesopore formation and highest total acidity discovered in HZ-0.01 (the mole ratio of CTAB/SiO 2 is 0.01) provided the highest aromatic compound yield of 26.8% and the lowest coke yield of 39.2%.
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TALANTA
·
2018
·
IF 4.244
Cui Liu,Qiang Zhang,Nianqi An,Jing Wang,Linlin Zhao,Yan Lu
Detection of the adenosine 5′-triphosphatase (ATPase) activity in lysosome of living cells is of great importance for clinical diagnosis of many related diseases, including cancer. In this work, a new water-soluble polythiophene derivative named ZnPT bearing both quaternary ammonium salt groups and dipicolylamine-Zn 2+ (DPA-Zn 2+ ) complexes in its side chain, was designed and synthesized for this propose. The probe mainly localized to lysosome with good biocompatibility and membrane penetration. The real-time, continuous, direct, and label-free assays were achieved through a fluorescence "turn-on" mode by taking advantages of the reaction specificity of ATPase with ATP and the high binding selectivity of ZnPT toward ATP substrate over its hydrolysis product (ADP). This well designed strategy should provide a facile and effective way for investigating ATPase-relevant biological processes.
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CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zhanyu Qian,Yinghao Wu,Wenjie Zhao
Glass fiber reinforced polymer coatings (GFRPC) are used to protect steel structures in harsh marine environments due to high mechanical strength and chemical stability. The composite coating not only suffers from impact damage by seawater and sediment but also experiences corrosion damage in the splash zone. However, the GF has weak interfacial adhesion with polymer resins due to the chemical inertia and smooth surface, which limits the service lifespan of GFPRC. Hence, ZSM-5 zeolite were in situ prepared on the surface of glass fibers by hydrothermal synthesis, and 2-mercaptobenzimidazole (MBI) was further adsorbed to obtain difunctional hybrid glass fibers (ZGFM) to enhance the interfacial adhesion strength of glass fiber/resin and also the erosion resistance and anti-corrosion ability of composite coatings. Compared to GF/EP, the interfacial shear strength of ZGFM/EP was increased by 104.39 %. After immersion under an alternating hydrostatic pressure of 20 MPa for 12 days, the impedance value of the ZGFM/EP composite coating remained at 6.40 × 10 9 Ω•cm 2 , demonstrating outstanding deep-sea anti-corrosion performance. Following the erosion test, the ZGFM/EP exhibited a reduction in mass loss and volume loss by 10.65 % and 12.55 %, respectively, in comparison to the pure EP coating. The excellent interfacial strength between ZGFM and EP ensured effective stress transfer, which prevented crack propagation, thus enhancing the mechanical properties and erosion resistance of the composite coating. Meanwhile, electrochemical experiment proves glass fiber with MBI loaded obviously inhibits the corrosion reaction.
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JOURNAL OF ALLOYS AND COMPOUNDS
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2024
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IF 5.8
Yunzhu Du,Fan Yang,Jing Li,Min Jiang,Jiewei Yin,Qiaodan Hu,Junliang Zhang
High-entropy spinel oxide (Cr 1/5 Mn 1/5 Ni 1/5 Fe 1/5 Co 1/5 ) 3 O 4 (CMNFCO) and its low- and medium-entropy counterparts including FeCo 2 O 4 (FCO), (Ni 1/3 Fe 1/3 Co 1/3 ) 3 O 4 (NFCO), (Mn 1/4 Ni 1/4 Fe 1/4 Co 1/4 ) 3 O 4 (MNFCO) were prepared via a simple hydrothermal method, and their electrocatalytic performances towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in 0.1 M KOH were investigated. Among all the synthesized spinel oxides, the high-entropy CMNFCO showed the best ORR activity with an onset potential E onset = 0.88 V, a half-wave potential E 1/2 = 0.76 V and excellent ORR durability with 91.5 % current retained after 33 h-chronoamperometry test at 0.287 V vs. RHE. On the other hand, CMNFCO showed mediocre OER activity with an overpotential of 411 mV at 10 mA·cm −2 , which is more than 20 mV higher than the medium-entropy composition MNCFO. An Al-air battery using CMNFCO as the cathode catalyst was assembled and exhibited a maximum power density of 148.8 mW·cm −2 . Surface reconstruction of the high-entropy spinel in the electrolyte was revealed by in situ Raman spectroscopy. Based on the present study, we conclude that increasing the number of constituent elements does not necessarily improve the OER activity, but it may lead to surface reconstruction to benefit ORR.
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JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2024
·
IF 5.8
Shuna Zhao,Hao Liu,Mi Li,Lin Jiang
5-Aminotetrazole/strontium nitrate (5AT/Sr(NO 3 ) 2 ) propellant is widely utilized as green gas generating agent in fire extinguishers. To enhance the combustion rate and modify the gas production performance of 5AT/Sr(NO 3 ) 2 propellant, this study investigated the catalytic effects of adding different metal oxides (Bi 2 O 3 , PbO, TiO 2 , and CoO) on its pyrolysis and combustion process. The pyrolysis behavior, pyrolysis mechanism and combustion performance of 5AT/Sr(NO 3 ) 2 propellants were studied by using thermogravimetry (TG), derivative thermogravimetry (DTG), differential scanning caborimetry (DSC), mass spectrometry (MS), fourier transform infrared spectroscopy (FTIR) analysis and closed bomb vessel tests. Experimental results indicated that Bi 2 O 3 and PbO predominantly facilitated the thermal decomposition process of 5AT, while TiO 2 and CoO primarily catalyzed the thermal decomposition of Sr(NO 3 ) 2 . Certainly, the addition of metal oxides as catalysts to 5AT/Sr(NO 3 ) 2 propellant holds significant potential for improving the application as a gas generating agents in fire extinguishers.
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ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Chaoqiang Wu,Xin Zhang,Wei Liu,Chengyong Wang,Qianqian Jiang,Feifei Chen,Quanzhen Liu,Fei Cao,Gaowei Zheng,Alei Zhang,Kequan Chen
Chitin, as the second most abundant biomass in nature, possesses 7 wt % biologically fixed nitrogen, and its direct valorization into valuable nitrogen (N)-containing chemicals is optimal. Herein, we report the biosynthesis of two specific furan-based amine compounds, 2-acetyl-4-aminofuran (2A4AF) and 3-acetylamino-5-(α-aminoethyl)-furan (3A5AEF), from chitin-derived 3-acetamido-5-acetylfuran (3A5AF) via biocatalytic deacetylation and reduction amination, respectively. An amidase (MmH) from Starkeya sp. and an R-selective aminotransferase (ATA117) from Arthrobacter sp. were obtained, which can, respectively, convert 3A5AF to 2A4AF with a yield of 79.3% (47.58 mM) and (R)-3A5AEF (enantiomeric excess (ee) value of >99%) with a yield of 84.0% (126 mM), respectively, under the optimal conditions. The biosynthesis efficiency of the two amines was high in comparison with chemical approaches. This work paves the way for green and efficient production of furan-based amino chemicals from inexpensive renewable chitin resources.
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Engineering
·
2024
·
IF 10.1
Pan Wang,Tao Cheng,Zhuangxin Wei,Lu Liu,Yue Wang,Xiaohua Tian,Jianming Pan
Expanding the specific surface area of substrates and carrying out precise surface engineering of imprinted nanocavities are crucial methods for enhancing the identification efficiency of molecularly imprinted polymers (MIPs). To implement this synergistic strategy, bioinspired surface engineering was used to incorporate dual covalent receptors via precise post-imprinting modifications (PIMs) onto mesoporous silica nanosheets. The prepared sorbents (denoted as “D-PMIPs”) were utilized to improve the specific identification of adenosine 5′-monophosphate (AMP). Significantly, the mesoporous silica nanosheets possess a high surface area of approximately 498.73 m 2 ∙g –1 , which facilitates the formation of abundant specific recognition sites in the D-PMIPs. The dual covalent receptors are valuable for establishing the spatial orientation and arrangement of AMP through multiple cooperative interactions. PIMs enable precise site-specific functionalization within the imprinted cavities, leading to the tailor-made formation of complementary binding sites. The maximum number of high-affinity binding sites ( N max ) of the D-PMIPs is 39.99 μmol∙g –1 , which is significantly higher than that of imprinted sorbents with a single receptor (i.e., S-BMIPs or S-PMIPs). The kinetic data of the D-PMIPs can be effectively described by a pseudo-second-order model, indicating that the main binding mechanism involves synergistic chemisorption from boronate affinity and the pyrimidine base. This study suggests that using dual covalent receptors and PIMs is a reliable approach for creating imprinted sorbents with high selectivity, allowing for the controlled engineering of imprinted sites.
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Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Weilun Yu,Xing You,Yuanchen Wu,Chuanpeng Li,Qiyao Wang,Xiaohang Yang,Xingbo Bian,Yi Lu
The most promising and environmentally friendly strategy to address the greenhouse effect is to utilize renewable solar energy and semiconductor photocatalytic technology to convert excessive CO₂ into valuable chemicals. However, the unsatisfactory photoreduction activity and product selectivity of pristine semiconductor remain significant barriers to their large-scale industrial application. In this study, graphitic carbon nitride (g-C 3 N 4 ) was selected as a model photocatalyst, and HZSM-5 zeolite with a high Si/Al ratio of 500 was employed to synthesize g-C 3 N 4 /HZSM-5 composite via a simple thermal polymerization method. The incorporation of HZSM-5 zeolite, characterized by its rich pore structure, significantly increased the composite's specific surface area, thereby reducing the transportation distance of photoexcited charge carriers and enhancing photoelectric conversion efficiency. The pore structure of HZSM-5 zeolite facilitated the enrichment of CO 2 , increasing the local reactant concentration. Additionally, the specific pore micro-environment exhibited a lower adsorption strength for the reduction product (CO), preventing its further conversion into undesired by-products. Furthermore, the weak acidity of the micro-environment contributed to the stabilization of intermediates, such as -HCO 3 and -COOH, promoting specific reaction pathways. As a result, the g-C 3 N 4 /HZSM-5 composite achieved high CO 2 photoreduction activity and CO selectivity (>95 %). This work highlights the potential of designing composite photocatalysts with tailored micro-environments for efficient and selective CO 2 photoreduction.
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