MICROPOROUS AND MESOPOROUS MATERIALS
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2016
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IF 3.349
Xing Chu,Dan Zhou,Dan Li,Kun Xia,Ning Gan,Xinhuan Lu,Renfeng Nie,Qinghua Xia
This work has firstly constructed purely Lewis acidic sites on MCM-41 successfully, for which Zr-MCM-41 catalysts with different Zr contents are prepared through the hydrolysis of ZrOCl 2 on MCM-41, followed by calcination . Thus-prepared materials possess typical hexagonal mesostructures, irregular morphologies, large surface areas, and large pore sizes, as revealed by XRD , SEM, TEM, N 2 adsorption, and DRIFT FTIR. UV–vis, Raman and XPS spectra prove the formation of isolated species in high dispersion on the surface of MCM-41. NH 3 -TPD analysis shows that the acid intensity of the catalysts is proportional to the content of Zr, and the acidity of Zr-MCM-41 with the Zr content of <0.5% is very weak. Pyridine-IR spectra show that the surface acidity is mainly consisted of Lewis acidity, and solely Lewis acidic sites are constructed on Zr-MCM-41(550) with a low Zr content < 0.5 wt%. More Lewis acidic sites exposed on the surface of Zr-MCM-41 are considerably important for promoting the titled Prins condensation.
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
·
2024
·Vol. 14
·期 2
·142
·
IF 3.8
Dengke Li,Qinghao Shi,Fengbing Liang,Dexin Feng
Biodiesel is a non-toxic and environmentally friendly fuel that is made from renewable biological sources. It can replace petrochemical diesel and has very broad application prospects. However, the main raw materials in biodiesel are animal and plant oils, which present the problems of high costs and a lack of resources. The current research primarily emphasizes the transesterification process, with comparatively less focus on the esterification of fatty acids. In this paper, a series of phosphotungstic acid (PTA)-functionalized hydrophobic MCM–41 catalysts, OTS–PTA–MCM–41(Cx), were synthesized and used to catalyze the esterification of long-chain fatty acids with methanol in water. The experimental results show that the yield of esterification reached a maximum when catalyzed by OTS–PTA–MCM–41(Cx) and synthesized with a template agent with two carbon atoms less than the number of carbon atoms of a fatty acid. The effects of different reaction variables were investigated to optimize the reaction conditions for the maximum conversion. The stability of the catalyst was also verified. Finally, a mixed catalyst was used to catalyze in situ the esterification of fatty acids in a fermentation broth, which reached a high level (close to 90%). This paper provides references for the synthesis of a hydrophobic solid acid catalyst and green synthesis by esterification reactions in an aqueous solution and a fermentation broth system.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2016
·
IF 5.31
Guan-Yu Pan,Yu-Long Ma,Xiao-Xia Ma,Yong-Gang Sun,Jun-Min Lv,Jian-Li Zhang
Ni–W/MCM-41 as a non-noble metal catalyst for catalytic conversion of corn stalk pretreated with alkali into polyol was prepared by an impregnation method. The results showed that pretreatment corn stalk with alkali removed 41.79 wt% of hemicellulose and 60.21 wt% of lignin and thereby increased the content of cellulose from 41.13 wt% to 59.29 wt%. Data obtained from X-ray photoelectron spectra exhibited that there was an intense interaction between nickel and tungsten. Meanwhile, the Ni 17 W 3 alloy was evidenced by X-ray diffraction spectra. These were very beneficial to enhance the catalytic conversion of lignocellulose into polyol. The maximum yield of 71.37 wt% polyol was obtained by catalytic hydrogenation of lignocellulose to ethylene glycol and 1,2-propylene glycol utilizing 5%Ni–15%W/MCM-41 catalyst under H 2 pressure of 6 MPa and 250 °C for 2 h.
研究领域:
生物化学
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催化化学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2025
·
IF 9
Haozhan Chu,Shaojuan Zeng,Xiangping Zhang,Guoxiong Zhan,Bo Wang,Hongyu Zhang,Sheng Zhong,Wei Liu
Ionic liquids (ILs) show great application potentials in CO 2 capture due to extremely low vapor pressures, tunable structures, and strong CO 2 affinity. Up to date, many efforts have been focused on the design and absorption performance of novel functionalized ILs, rather than desorption performance. In our previous work, the IL solvent [Cho][Triz]/TMS exhibited exceptional CO 2 absorption performance. As a successive study on decreasing regeneration energy consumption, this work focused on the design and synthesis of novel metal-modified MCM-41 catalysts with multiple acidic sites to enhance CO 2 catalytic desorption in the nonaqueous [Cho][Triz]/TMS (80 wt%/20 wt%) absorbent under lower temperatures. Among all the composite MCM-41 catalysts, the CoM-1/4 catalyst exhibits superior catalytic performance because of the increase of Brønsted acid sites by 232.3 % and Lewis acid sites by 56.2 % compared with pristine MCM-41, which promote CO 2 desorption by accelerating C-N bond breaking. The CO 2 desorption rate and amount increased by 180.2 % and 95.7 %, and the activation energy reduced by 46.7 % compared to the non-catalysis. Therefore, the theoretical regeneration energy consumption of the catalyst-added system was 0.88 GJ/t CO 2 , representing a 76.7 % reduction compared with the 30 wt% MEA solution. Furthermore, the CoM-1/4 catalyst maintained high catalytic activity after 20 cycles. This work indicated that the CoM-1/4 catalyst effectively enhanced the regeneration performance of IL absorbent, facilitating the development of an energy-efficient CO 2 capture process for industrial applications.
研究领域:
化学工程
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环境科学
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催化材料
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产品关联
DOI
高影响因子
Molecular Catalysis
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2025
·
IF 4.9
Kaixuan Yan,Xin Song,Chunliang Zhou,Junnan Liu,Rongji Cui,Panting Gao,Zhicheng Tang
The presence of sulfur-containing impurities in natural gas not only diminishes its utilization value, but also results in the emission of sulfur-containing pollutants. In this study, a Cu-Ce bimetallic-loaded MCM-41 catalyst was prepared by ammonia evaporation method for the catalytic hydrolysis of carbonyl sulfide (COS). The desulfurization efficiency of Cu 25 Ce 5 /MCM-41 can reach a 100 % COS removal rate and maintain for 3.5 h. CuO furnishes the predominant weakly acidic and weakly basic sites for the desulfurization process, which are conducive to the adsorption of COS. Meanwhile, CeOx provides a greater abundance of moderately basic sites for the desulfurization process, which help to improve the removal efficiency of COS. The incorporation of Ce into the catalyst enhances the resistance to sulfur poisoning of Cu and prolongs the lifespan of the catalyst. The incorporation of Ce is capable of transforming the strongly basic sites on the surface of Cu 25 /MCM-41 into moderately basic sites, avoiding excessive oxidation of H 2 S. Additionally, the introduction of Ce offers a degree of protection for CuO, which improves the ability of the catalyst to resist sulfur poisoning. The combined effect of Cu and Ce was found to be instrumental in enhancing the adsorption of COS and in slowing down the oxidation of H 2 S. The reduction of Cu 2+ and Ce 3+ indicated their direct participation in the oxidation of H 2 S. Firstly, COS adsorbed on the catalyst surface is converted into H 2 S and CO 2 through a catalytic hydrolysis reaction. Subsequently, H 2 S adsorbed on the catalyst surface undergoes partial oxidation to sulfide, and partial further oxidation by oxygen-containing functional groups on the surface to S, SO 3 2- , and SO 4 2- , which results in the toxic deactivation of the catalyst.
研究领域:
催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2014
·
IF 3.209
Ben Qi,Lan-Lan Lou,Yanbing Wang,Kai Yu,Ying Yang,Shuangxi Liu
Manganese containing mesoporous materials Mn-MCM-41 were prepared by template-ion exchange (TIE), in situ reduction (ISR), direct hydrothermal (DHT) and wetness impregnation (WI) methods. The samples were characterized by XRD , N 2 adsorption–desorption, HR-TEM, TG, UV–Vis, H 2 -TPR and ESR techniques, which illustrated that the definite structure of the MCM-41 was retained after introducing Mn into MCM-41 by different method. The catalytic activity and selectivity of the Mn-MCM-41 in the epoxidation of styrene with 30% H 2 O 2 as an oxidant agent were explored. The TIE catalysts showed the highest activity but Mn 2+ was leached during the reaction. The ISR catalysts exhibited high activity for epoxidation of styrene. Furthermore, recycling studies proved the ISR catalysts as heterogeneous catalysts , which did not lose the catalytic activity after four recycles appreciably. However, the DHT and WI catalysts showed poor performance in the catalytic epoxidation of styrene. Various parameters such as different reaction molar ratio of H 2 O 2 /styrene, catalyst amount, and kinds of solvents were studied to optimize the reaction conditions.
研究领域:
催化化学
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材料化学
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有机合成
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多相催化
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环境友好氧化过程
✓ 已验证
DOI
高影响因子
RSC Advances
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2014
·Vol. 4
·期 29
·15216-15224
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IF 3.708
Chong-Wen Jiang,Xin Zhong,Zheng-Hong Luo
5-Hydroxymethylfurfural (5-HMF) which can be produced from cellulose is considered as one of the promising green platform chemicals. In this work, the conversion of cellulose to 5-HMF was carried out through hydrolysis in a batch reactor using the SO42−/Ti-MCM-41 catalyst at a temperature of 463–503 K. Two analytical techniques including the 3,5-dinitrosalicylic acid (DNS) method and high performance liquid chromatography (HPLC) were employed to track the time evolution of the main reagents, i.e., cellulose, 5-HMF and reducing sugar. Based on the typical kinetic experiments for the cellulose hydrolysis, a comprehensive hydrolysis mechanism was introduced to describe the heterogeneous hydrolysis of cellulose to 5-HMF. A corresponding kinetic model was proposed on the basis of the hydrolysis mechanism and the mass balance law. The results show that the predicted data obtained via the suggested model agree well with the experimental results. In addition, some data from the open reports were referred for further model verification in this work. The kinetic model suggested in this work is a mechanism model for the heterogeneous catalytic cellulose hydrolysis process, which is different from the previous first-order kinetic model.
研究领域:
化学工程
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可再生化学
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产品关联
DOI
高影响因子
Science China-Chemistry
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2012
·Vol. 55
·期 6
·1167-1174
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IF 1.02
Lang WanZhong,Su Bo,Guo YaJun,Chu LianFeng
Four amine functionalized mesoporous catalysts were synthesized by grafting primary, dualistic and two secondary amines onto the channel walls of mesoporous silica, MCM-41. We examined the effects of organoamine loading amount on the acid-base synergism of the catalysts in the self-condensation reaction of n -butanal, a Knoevenagel condensation and a Henry reaction. We observed the balance of the amine and residual silanol amounts is crucial to the catalytic performances of the functionalized mesoporous catalysts. An optimum organoamine loading amount exists, which is dependent on the organoamine type. There is little difference in the optimum organoamine loading amount between different reactions. The secondary organoamine functionalized MCM-41 exhibits the best catalytic performance in the experimental range.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2018
·Vol. 8
·期 21
·5526-5534
·
IF 5.365
Songyan Jia,Xinjun He,Jiao Ma,Kangjun Wang,Zhanwei Xu,Z. Conrad Zhang
The synthesis of furan compounds by renewable carbohydrates has emerged as an important path toward biomass utilization. 5-Hydroxymethylfurfural (5-HMF) and furfural are two typical furan products from cellulosic and hemicellulosic materials, of which the primary components (hexoses and pentoses) undergo selective dehydration. It is worth noting that hemicellulose is rich in not only pentoses but also hexoses, indicating the feasibility of producing 5-HMF and furfural simultaneously. However, research on the production of 5-HMF from hemicellulose-derived hexoses remains lacking. Mannose, a major hexose component of hemicellulose, has been previously found to be a suitable feedstock for 5-HMF production in the presence of homogeneous catalysts, such as metal salts. In this work, Cr-, Al- and Sn/MCM-41 catalysts were prepared by a simple impregnation method and characterized. The conversion of mannose into 5-HMF was evaluated in dimethyl sulfoxide (DMSO) solvent. It was found that the as-synthesized Sn/MCM-41 catalyst showed a superior activity to Cr/MCM-41 and Al/MCM-41. Mannose could be effectively converted into 5-HMF with a yield of ∼45% and ∼88% conversion at 150 °C after 60 min, which were comparable to reported results over heterogeneous catalysts. The as-synthesized Sn/MCM-41 catalyst was also efficient for the conversion of glucose and fructose with reasonable 5-HMF yields. The Sn/MCM-41 catalyst could be reused for eight consecutive cycles without significant loss of catalytic activity.
研究领域:
生物化学
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催化化学
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生物质利用
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2024
·Vol. 48
·期 26
·11802-11811
·
IF 2.7
Chenxia Xu,Jianhua Lv,Jidong Liu,Bao Guo,Wensong Li
Ga2O3/MCM-41-x (x = 0.4, 0.5, 0.6) heterogeneous catalysts, each with varying levels of Br doping, were synthesized using mesoporous molecular sieves (MCM-41) as a carrier and employed in the synthesis of propylene carbonate (PC) from propylene oxide (PO) and carbon dioxide (CO2). The reaction was conducted under solvent-free and additive-free conditions. Various techniques were utilized to characterize the catalysts’ chemical composition, morphology, and structure. The effects of varied reaction conditions on PO conversion and PC selectivity using Ga2O3/MCM-41-0.5 catalysts were investigated. Under the reaction conditions of 120 °C, 3.5 MPa, 10 h and catalyst dosage of 2.6 wt%, the PO conversion and PC selectivity reached 99.7% and 99.1%, respectively. The catalytic impact correlates strongly with the doping amounts of Ga2O3 and Br, primarily due to the interaction of Ga2O3 with the surface of MCM-41, leading to the generation of more basic sites and, consequently, a greater abundance of alkali centers. As a nucleophilic reagent, Br functions synergistically with Ga2O3/MCM-41, augmenting the ring-opening rate of PO and improving the activation ability of CO2. The stability of the catalyst underwent evaluation, revealing a slight decrease in activity after repeated use. The reaction mechanism underlying PC synthesis catalyzed by Ga2O3/MCM-41-0.5 was speculated.
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
YiRong Yao,Bing Xing,Jianbing Chen,YanLun Ren,YuJia Ma,Ying Zhang,Li Zhang
This study proposes an advanced method to tackle CO 2 emissions by enhancing solid acid catalysts, aiming to reduce the high energy consumption and low economic efficiency typically associated with chemical absorption processes. The research involves modifying commercial HZSM-5 zeolites through Cu ion exchange, with the optimal performance observed at a Cu ion content of 2.86 % and a Cu salt concentration of 0.2 M. This modification significantly minimizes the loss of copper ions—a common issue in the impregnation method—resulting in a 76.62 % reduction in the loss of active components. To further improve CO 2 gas-liquid mass transfer, mesoporous MCM-41 zeolites were introduced. Experimental results demonstrate that, at a regeneration temperature of 86°C and a mass ratio of 2:1 for HZSM-5 to MCM-41, the combined catalyst achieves a 61.28 % reduction in relative heat duty compared to the blank sample. Moreover, the energy consumption is 12.33 % and 16.45 % lower than that of HZSM-5 and MCM-41 used individually. Characterization analysis reveals that, under comparable acidic active site densities, catalysts with superior physical pore structures exhibit enhanced catalytic performance. The introduction of mesoporous structures notably improves the bidirectional mass transfer efficiency between carbamate macromolecules and CO 2 molecules. This work successfully demonstrates the synergistic effect of combining Cu ion-modified HZSM-5 zeolites with mesoporous MCM-41, leveraging the abundant active sites of HZSM-5 while harnessing the enhanced mass transfer properties of MCM-41.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2017
·
IF 6.065
Weirui Chen,Xukai Li,Yiming Tang,Jialu Zhou,Dan Wu,Yin Wu,Laisheng Li
A flexible catalyst, Fe-Cu-MCM-41, was employed to enhance diclofenac (DCF) mineralization and inhibit bromate formation in catalytic ozonation process. Greater TOC removal was achieved in Fe-Cu-MCM-41/O 3 process (78%) than those in Fe-MCM-41/O 3 (65%), Cu-MCM-41/O 3 (73%) and sole ozonation (42%). But it was interesting that both Cu-MCM-41/O 3 and Fe-MCM-41/O 3 achieved 93% bromate inhibition efficiency, only 71% inhibition efficiency was observed in Fe-Cu-MCM-41/O 3 . Influence of pH, TBA/NaHSO 3 and detection of by-products were conducted to explore the mechanism. By Pyridine adsorption–IR and XPS, a relationship was found among activity of catalysts, Lewis acid sites and electron transfer effect between Fe (II/III) and Cu (I/II). Fe-Cu-MCM-41 promoted ozone decomposition to generate OH, which accounted for enhanced DCF mineralization. The consumption of aqueous O 3 also suppressed the oxidative of Br − and HBrO/Br − . More HBrO/BrO − accumulated in catalytic ozonation process and less bromate generated. Bromate formation in Fe-Cu-MCM-41/O 3 process was sensitive with pH value, the acidic condition was not favor for bromate formation. Both DCF mineralization and bromate inhibition were influenced by surface reaction. Moreover, Fe-Cu-MCM-41 showed excellent catalytic performance in suppressing the accumulation of carboxylic acid, especially for oxalic acid. Nearly no oxalic acid was detected during Fe-Cu-MCM-41/O 3 process.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）