THERMOCHIMICA ACTA
·
2013
·
IF 1.989
Li Yin,Defeng Wu,Zhen Yao,Saihua Feng,Ming Zhang,Yufang Gao
Poly(trimethylene terephthalate)/mesoporous silica SBA-15 composites were prepared by in situ hybridization for the crystallization study. The results show that SBA-15 particles are well compounded with PTT, forming nanostructured composite system. Although the addition of SBA-15 particles results in an evident decrease of PTT molecular weight, those well dispersed mesoporous particles can compensate effectively for the property degradation of PTT. Besides, the addition of SBA-15 particles has large influence on the crystallization of PTT. The composites show higher crystallization temperature and rate than that of the neat PTT. But the presence of SBA-15 impedes PTT chain segment movements somewhat. In comparison with neat PTT, therefore, the composites present lower folding surface free energy and higher diffusion activation energy. The kinetic analysis results elucidate that the crystallization rate of PTT is dominated by the nucleation item instead of the growth one.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
ChemistrySelect
·
2023
·Vol. 8
·期 16
·e202300902
·
IF 2.1
Panli Liu,Shengbin Shi,Ruiping Wei,Lijing Gao,Jin Zhang,Guomin Xiao
Graphical P-Zr-SBA-15 catalyst with bifunctional acidity was synthesized by introducing Zr 4+ into the mesoporous material SBA-15 structure for intra skeleton modification, and then impregnated with phosphoric acid solution to modify the outer skeleton. The catalyst exhibits excellent catalytic activity, good thermal stability, and recoverability in the preparation of furfural. A series of bifunctional P-Zr-SBA-15 catalysts with Lewis acid and Brønsted acid sites were prepared by modifying mesoporous material SBA-15 with Zr 4+ and phosphate group, which were used in the conversion of xylose and xylan into furfural. The structure and acidic characteristics of the catalyst were analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, N 2 adsorption desorption, scanning/transmission electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, NH 3 temperature programmed desorption, and pyridine adsorption infrared spectroscopy. The effects of different process parameters on the catalytic performance of the catalyst were studied. when using the xylose and xylan as substrates, the furfural yield were 80.3 % and 68.8 % under the optimal conditions in the H 2 O (NaCl) /toluene (3/3 mL) biphasic solvent system, respectively, and 52.5 % furfural yield was obtained using xylose as substrate in aqueous system. In addition, the catalyst has good thermal stability and easy recovery in the recycling experiment.
研究领域:
催化化学
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生物质转化
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产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2022
·
IF 4.778
Xijun Li,Sifan Zhang,Lihua Zhu,Jun Liu,Huan Zhang,Ning Zhao,Bing Hui Chen
Herein, a series of the Pt-based bimetallic catalysts (PtM x /SBA-15) are gained by using ultrasonic incipient wetness impregnation method (M = Co, Cu, Ni or Zn). The experimental results show that the catalytic performance (including catalytic activity (turnover frequency-TOF), selectivity to crotyl alcohol) of PtCo x /SBA-15 for catalyzing crotonaldehyde selective hydrogenation is the best among PtM x /SBA-15. Additionally, the ratio of Pt/Co in the PtCo x /SBA-15 catalysts is changed to successfully synthesize PtCo/SBA-15, PtCo 2 /SBA-15, PtCo 5 /SBA-15. It demonstrates that the selectivity of the PtCo x /SBA-15 catalysts for crotonaldehyde selective hydrogenation to crotyl alcohol is significantly improved with the increase of the Co content. The PtCo 5 /SBA-15 catalyst provides 83.8% conversion of crotonaldehyde, 94.3% selectivity to crotyl alcohol and TOF of 910.5 h −1 under mild reaction conditions (3.0 MPa H 2 , 80 °C and 2.0 h). And PtCo 5 /SBA-15 has much better catalytic performance (higher catalytic activity and selectivity to crotyl alcohol) than PtCu 5 /SBA-15, PtNi 5 /SBA-15 and PtZn 5 /SBA-15. The reasons are as follows: (1) PtCo alloy forms, which is conducive to crotonaldehyde adsorption and activation; (2) there is an appropriate synergy effect between Pt and Co, greatly improving the capacity of the catalyst activating hydrogen under mild conditions; (3) the electron transfers from Co to Pt, resulting in the increase of Pt electron density and decrease of Co electron density, then the Co sites are advantageous to C O group adsorption and activation and Pt sites for H 2 adsorbing and activating; (4) with the increase of the Co proportion in PtCo x /SBA-15, the synergy effect between Pt and Co in PtCo alloy strengthens and thus increases the selectivity of C O group hydrogenation.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
Catalysts
·
2022
·Vol. 12
·期 11
·1469
·
IF 4.501
Yilin Huang,Jia Wang,Mengwei Li,Zhixiong You
We have successfully synthesized dithiocarbamate chitosan modified SBA-15 (CS2C@SBA) composites, with promise in vanadium (V(V)) elimination. Among the three composites using different mass ratios of dithiocarbamate chitosan to SBA-15, CS2C@SBA−3, which had the highest CS2substitution, showed the best performance on V(V) removal of which the maximum adsorption capacity could achieve 218.00 mg/g at pH 3.0. The adsorption kinetics were best fitted with a pseudo−second order reaction model, suggesting a chemisorption mechanism. Meanwhile, the Langmuir model fitted better with the adsorption isotherm, revealing a monolayer adsorption behavior. Through FTIR and XPS analysis, the functional group −SH was identified as dominating reduction sites on this composite, which reduced 73.1% of V(V) into V(IV) and V(III). The functional group −NH− was the main adsorption site for vanadium species. This reaction followed a catalytic reduction coupled adsorption mechanism reducing most of V(V) into less toxic vanadium species. Furthermore, CS2C@SBA−3 showed great selectivity towards V(V) in the presence of various co−existing ions in synthetic wastewater and real water samples. Moreover, CS2C@SBA−3 could retain a removal efficiency over 90% after five adsorption−desorption cycles. Based on the aforementioned results, we can conclude that CS2C@SBA−3 has great potential to be applied in efficient remediation of vanadium water−pollution.Keywords:vanadium elimination;adsorption;catalytic reduction;thiol function group;dithiocarbamate chitosan modified SBA-15
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2025
·
IF 4.8
Yifan Liu,Jiangang Wang,Yuhan Liu,Yuan Zhang,Hongzi Tan,Hongyou Cui
Herein, a series of Sn-based catalysts supported on SBA-15 with temperature responsive ability to in situ construct acidic and basic sites are reported for efficient conversion of biomass-derived sugars into ethyl lactate (EL). Based on the investigation on the effects of the molar ratio of Cl/OH in Sn(OH) x Cl 2-x and the support types, it is found that Sn(OH) 0.5 Cl 1.5 @SBA-15 is an excellent catalyst in catalytic conversion of various sugars to EL, achieving a maximum EL yield of 68.1 % from sucrose. The in situ generated basic SnO sites play important roles in accelerating the retro-aldol condensation reaction, while the concomitantly released acidic sites (Sn 2 + , SnCl + and H + ) could catalyze the reactions of hydrolysis, isomerization, intermolecular rearrangement and esterification to EL. Benefiting from the temperature responsive effect, not only can the reaction pathways be regulated toward high EL selectivity, but also the catalyst can be recycled easily. This research paves an avenue for exploring efficient catalysts for biomass valorization.
研究领域:
催化化学
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生物质转化
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材料科学
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产品关联
DOI
高影响因子
Scientific Reports
·
2015
·Vol. 5
·期 1
·1-11
·
IF 5.578
Yao Qilu,Lu Zhang-Hui,Yang Kangkang,Chen Xiangshu,Zhu Meihua
Ultrafine ruthenium nanoparticles (NPs) within the mesopores of the SBA-15 have been successfully prepared by using a “double solvents” method, in which n -hexane is used as a hydrophobic solvent and RuCl 3 aqueous solution is used as a hydrophilic solvent. After the impregnation and reduction processes, the samples were characterized by XRD, TEM, EDX, XPS, N 2 adsorption-desorption and ICP techniques. The TEM images show that small sized Ru NPs with an average size of 3.0 ± 0.8 nm are uniformly dispersed in the mesopores of SBA-15. The as-synthesized Ru@SBA-15 nanocomposites (NCs) display exceptional catalytic activity for hydrogen generation by the hydrolysis of ammonia borane (NH 3 BH 3 , AB) and hydrazine borane (N 2 H 4 BH 3 , HB) at room temperature with the turnover frequency (TOF) value of 316 and 706 mol H 2 (mol Ru min) −1 , respectively, relatively high values reported so far for the same reaction. The activation energies ( E a ) for the hydrolysis of AB and HB catalyzed by Ru@SBA-15 NCs are measured to be 34.8 ± 2 and 41.3 ± 2 kJ mol −1 , respectively. Moreover, Ru@SBA-15 NCs also show satisfied durable stability for the hydrolytic dehydrogenation of AB and HB, respectively.
研究领域:
纳米催化
·
能源材料
·
无机化学
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氢气储存与释放
·
多相催化
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DOI
高影响因子
ACS Applied Nano Materials
·
2021
·
IF 5.097
Hongbo Yu,Chunzheng Wu,Shiwei Wang,Tong Li,Hongfeng Yin
Modification of active metals with metal oxide modifiers has attracted considerable attention in heterogeneous catalysis due to their synergistic effect. However, a controllable synthesis of highly reactive and stable metal–metal oxide hybrid nanocatalysts is difficult. To solve this problem, presynthesized IrM (M = Fe, Co, and Ni) bimetallic nanoparticles were initially confined in the mesopores of SBA-15 and were then in situ transformed to Ir-MOx hybrids. The obtained Ir-MOx/SBA-15 nanocatalysts show superior activity and selectivity in the hydrogenation of substituted nitroaromatics to corresponding aromatic amines compared to Ir/SBA-15. Among these Ir-based catalysts, Ir-FeOx/SBA-15 exhibits the highest activity and selectivity and has a wider substrate scope due to the interaction between Ir and FeOx. Therefore, our research provides a way to design reactive and stable hydrogenation catalysts.
研究领域:
催化化学
·
材料科学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Wenjing Ding,Wenshuai Zhu,Jun Xiong,Lei Yang,Aimin Wei,Ming Zhang,Huaming Li
A novel catalyst, based on iron-based redox ionic liquid modified mesoporous SBA-15 material was successfully prepared and applied to the removal of sulfur compounds in model oil. Sample structures were extensively studied by XRD, N 2 adsorption–desorption, TEM, FTIR, DRS, and XPS analysis. This strategy provided a catalyst system with high surface area, high accessibility for substrate and oxidant. In the process of extractive catalytic oxidative desulfurization (ECODS) of model oil, [Omim]BF 4 served as not only the extractant and the reaction media but also co-catalyst. Under the optimal conditions, the sulfur removal could reach 94.3%. The mechanism of the ECODS system was also proposed.
研究领域:
化学工程
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材料科学
·
环境科学
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产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2018
·
IF 3.849
Biao Lu,Zhaowei Wu,Lijuan Ma,Xia Yuan
Phosphotungstic acid (HPW) was immobilized on a sulphonic-acid-functionalized SBA-15 mesoporous molecular sieve through a one-step hydrothermal synthesis method, using non-ionic surfactant pluronic P123 as a structure-directing agent in acidic media, tetraethoxysilane (TEOS) as a silicon source and 3-trimethoxysilyl-1-propanethiol (MPTMS) with hydrogen peroxide (H 2 O 2 ) oxidized to a sulfonic acid group. The obtained composite material HPW-SBA-15-SO 3 H has a high specific surface area, large pore volume and increased strong acidity. The effect of raw-material ratio on the catalyst was investigated. Catalysts that were prepared under optimal conditions of a molar ratio of (MPTMS)/ (MPTMS + TEOS) of 1:10, a molar ratio of (H 2 O 2 )/(MPTMS) of 18:1 and a mass ratio of (HPW)/(TEOS) of 1:10 exhibited an excellent catalytic activity in the esterification reaction of cyclohexene with formic acid. The cyclohexene conversion exceeded 86.7% and the cyclohexyl formate selectivity was 98.1% after 6 h at 353 K with a mole ratio of cyclohexene to formic acid of 1:3 and a catalyst dosage of 5.7% (w/w). The composite catalyst had a higher catalytic stability than the sulfonic-acid-functionalized SBA-15 and SBA-15-immobilized HPW individually. The cyclohexene conversion reached 72.0% even after reused four times. Fourier transform infrared and temperature-programmed desorption of ammonia revealed that a strong interaction existed between the sulfonic-acid group and the HPW, which prevented acid-active component of HPW and sulfonic-acid group loss from the carrier.
研究领域:
化学工程
·
催化材料科学
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2022
·Vol. 12
·期 22
·6827-6837
·
IF 6.177
Penghui Li,Junhua Gao,Jing Shi,Huixiang Wang,Xiangying Xing,Jingzhao Ren,Yu Meng,Liancheng Wang,Baoliang Lv
Linear terminal olefin epoxidation is a significant oxidation reaction for the synthesis of valuable industrial intermediates. As typical olefin epoxidation catalysts, supported tungsten oxides are rich in oxygen vacancies, which have been investigated for improving catalytic performance in other reactions, but the influence on olefin epoxidation is rarely studied. Herein, a series of WO3−x/SBA-15 catalysts with different oxygen vacancy concentrations were obtained by impregnation and sequent hydrogen reduction at 300–600 °C. Their catalytic performances for 1-hexene epoxidation with hydrogen peroxide at 70 °C were studied. It was found that an appropriate concentration of oxygen vacancies could improve epoxidation (the epoxide productivity increased from 135 to 196 μmolepoxide gW−1 min−1) and reduce the apparent activation energy (from 51.6 to 46.9 kJ mol−1). The oxygen vacancies are also beneficial for cycloolefin and other linear olefin epoxidation. In particular, the productivity of cyclooctene oxide was promoted from 4161 to 5744 μmolepoxide gW−1 min−1. This promotion effect was attributed to the increase in the number of Lewis acid sites caused by introducing moderate oxygen vacancies, which could improve the activation of hydrogen peroxide and facilitate epoxidation. In situ FT-IR spectroscopy and density functional theory calculations further indicated that increasing the oxygen vacancies contributes to reducing the energy barrier of the transfer of electrophilic oxygen atoms in active intermediate W–OOH to 1-hexene, thereby promoting epoxidation.
研究领域:
催化化学
·
材料科学
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产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2014
·Vol. 43
·期 37
·14123-14131
·
IF 4.097
Lei Chen,Bing Yan
Both zeolite A/L and SBA-15 have been used to assemble novel photofunctional multi-component lanthanide hybrid materials. Microporous zeolites A/L are first functionalized by embedding lanthanide or zinc complexes (TTA = thenoyltrifluoroacetone, TAA = trifluoroacetone, bipy = 2,2′-bipyridyl) into the pores of zeolite A/L, and then the surface of functionalized zeolite A/L is modified via covalent linkers from aromatic carboxylic acids (para-aminobenzoic acid ABA and para-hydroxyl benzoic acid HBA) grafted by 3-(triethoxysilyl)-propyl isocyanate (TEPIC). On the other hand, SBA-15 is modified by grafting covalent linker phen-Si from the modification of 1,10-phenanthroline (phen) with TEPIC. Further, another lanthanide ion is used to link both functionalized zeolites, A/L and SBA-15, through the coordination with the two covalent linkers, ABS-Si (HBA-Si) and phen-Si, respectively. Subsequently, the obtained multicomponent microporous–mesoporous hybrid materials are assembled and characterized using XRD, FT-IR, UV-vis DRS, SEM, TEM and luminescent approaches (spectra, lifetimes and quantum efficiencies). These hybrids with both microporous zeolite and SBA-15 mesoporous host possess favourable luminescent performance and some hybrid systems present the high quantum efficiencies of 90%. Besides, the luminescent color can be tuned by adjusting the composition of these hybrids, among which four hybrids (S-phen-Eu-HBA-[ZA-Tb-bipy], S-phen-Eu-HBA-[ZA-Zn-bipy], S-phen-Eu-ABA-[ZA-Tb-TAA], S-phen-Eu-ABA-[ZL-Tb-bipy]) can be integrated to white light emission.
研究领域:
材料科学
·
光化学
·
纳米技术
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产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Junhua Zhang,Yao Liu,Shibo Yang,Junnan Wei,Liang He,Lincai Peng,Xing Tang,Yonghao Ni
Biorefinery for the purpose of producing biofuels, chemicals, and materials has received much attention. Furfural alcohol (FOL) and levulinate ester (LE) are important biomass-derived platform chemicals, and they are produced from sugar-based furfural (FAL). Unfortunately, the two products are often obtained separately in different reaction systems, which is undesirable; furthermore, it is of significant practical interest to control their selectivity so that the desired product can be accumulated in high yields. Herein, we present an efficient method for the highly selective conversion of FAL to FOL or isopropyl levulinate (IPL) in a one pot system using isopropanol as the hydrogen source and ZrO2@SBA-15 as a bifunctional catalyst with both Lewis acid and Brønsted acid sites. Under optimized reaction conditions, high yields of FOL and IPL in up to 90.4% and 87.2%, respectively, were obtained. Based on the experimental results, a kinetic model describing the catalytic conversion of FAL into FOL and IPL process has been established, which has a good correlation (R2 > 0.92) between the measured and predicted data. The developed kinetics can provide an effective tool to monitor the process and tailor the process conditions to obtain the desired product.
研究领域:
生物炼制
·
催化化学
·
绿色化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）