CHINESE JOURNAL OF CATALYSIS
·
2025
·
IF 17.7
Shaolei Gao,Peng Lu,Liang Qi,Yingli Wang,Hua Li,Mao Ye,Valentin Valtchev,Alexis T. Bell,Zhongmin Liu
Methyl methoxyacetate (MMAc) and methyl formate (MF) can be produced directly by heterogeneous zeolite-catalyzed carbonylation and disproportionation of dimethoxymethane (DMM), with near 100% selectivity for each process. Despite continuous research efforts, the insight into the reaction mechanism and kinetics theory are still in their nascent stage. In this study, ZEO-1 material, a zeolite with up to now the largest cages comprising 16×16-MRs, 16×12-MRs, and 12×12-MRs, was explored for DMM carbonylation and disproportionation reactions. The rate of MMAc formation based on accessible Brönsted acid sites is 2.5 times higher for ZEO-1 (Si/Al = 21) relative to the previously investigated FAU (Si/Al = 15), indicating the positive effect of spatial separation of active sites in ZEO-1 on catalytic activity. A higher MF formation rate is also observed over ZEO-1 with lower activation energy (79.94 vs. 95.19 kJ/mol) compared with FAU (Si/Al = 30). Two types of active sites are proposed within ZEO-1 zeolite: Site 1 located in large cages formed by 16×16-MRs and 16×12-MRs, which is active predominantly for MMAc formation, and Site 2 located in smaller cages for methyl formate/dimethyl ether formation. Kinetics investigation of DMM carbonylation over ZEO-1 exhibit a first-order dependence on CO partial pressure and a slightly inverse-order dependence on DMM partial pressure. The DMM disproportionation is nearly first-order dependence on DMM partial pressure, while it reveals a strongly inverse dependence with increasing CO partial pressure. Furthermore, ZEO-1 exhibits good catalytic stability, and almost no deactivation is observed during the more than 70 h test with high carbonylation selectivity of above 89%, due to the well-enhanced diffusion property demonstrated by intelligent-gravimetric analysis.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2025
·
IF 7.3
Yu Zhang,Huai Liu,Rui Zhang,Wenlong Jia,Junhua Zhang,Lincai Peng
Simultaneous utilization of lignocellulose-related glucose and xylose to produce methyl levulinate (ML), a versatile industrial commodity, is important to fully expend biomass components. We herein report a promising catalytic protocol involving the Hβ zeolite in dimethoxymethane (DMM) and methanol (MeOH) cosolvent that enables the coconversion of glucose and xylose to ML under one-pot conditions. ML yield as high as 56% with a turnover frequency (TOF) of over 3.2 h–1 can be accomplished at 150 °C. Isomerization–dehydration of glucose/xylose represents the primary reaction path, whereas the production of glycosides through etherification constitutes the secondary reaction path. The suggested catalytic mechanism is the preferential adsorption of C–O–C and C–OH groups at different acid sites, which leads to the emergence of two distinct pathways for the conversion of glucose/xylose into ML. Hβ-25, featuring a high concentration of Lewis and Brønsted acid sites, facilitates two distinct pathways for the conversion of glucose/xylose into ML. DMM functions as a hydroxymethylation reagent in the conversion of xylose to ML and promotes the isomerization of glycosides via ether exchange reactions. This contribution devises an efficient strategy for producing ML from glucose and xylose while elucidating the reaction mechanism of a tailored monolithic catalytic system.
研究领域:
生物化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2022
·
IF 4.889
Qin Wu,Yanyan Guo,Jiqing Shang,Daxin Shi,Yaoyuan Zhang,Kangcheng Chen,Hansheng Li,Yun Zhao,Qingze Jiao
The coupling of catalysis and extraction for the synthesis of polyoxymethylene dimethyl ethers (PODEn) was investigated from low-cost formaldehyde (FA) and dimethoxymethane (DMM). The process used sulfonic acid resins as catalysts and suitable organic solvents as the extractant. The effects of resin acidity, acid content, and pore structure on the catalytic performance were investigated. The correlation between the partition coefficient of FA and catalytic activity for preparation of PODEn was studied. It was found that the yield of PODE 3-8 was significantly higher than that without the use of extractant. Dimethoxymethane (EDC) exhibited the highest performance. The effect of various factors on the catalytic reaction , such as the amount of catalyst, the molar ratio of FA to DMM, reaction temperature, reaction time and the types and dosage of different extractants, were explored. Under the optimal conditions of n FA :n DMM = 2:1, 80 °C, 4 wt% D002 catalyst, v EDC:DMM+FA = 1:1 and 8 h, the PODE 3-8 yield enhanced from 6.12% to 55.86%.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2018
·
IF 4.521
Ruiyi Wang,Zhiwei Wu,Zhikai Li,Zhangfeng Qin,Chengmeng Chen,Zhanfeng Zheng,Guofu Wang,Weibin Fan,Jianguo Wang
Polyoxymethylene dimethyl ethers (PODE n , with the formula of CH 3 O–(CH 2 O) n –CH 3 ), as a promising environmentally benign diesel fuel or additive with an enormous potential in the reduction of soot and NO x emissions, can be efficiently synthesized from methanol derivatives such as dimethoxymethane (DMM) and trioxymethylene (TOM), which requests a proper catalyst of high performance. In this work, the catalytic performance of graphene oxide (GO) in the synthesis of PODE n as well as its relation to the catalyst structure was thoroughly investigated. The results indicate that GO is an excellent catalyst in the synthesis of PODE n from DMM and TOM; a TOM conversion of 94.6% and selectivity of 86.0% to PODE 2–8 are achieved under mild reaction conditions, which is superior to the majority of the state-of-the-art catalysts. Meanwhile, the active species and characteristic layer structure of GO sheets catalytically responsible for PODE n formation were discriminated through selectively removing certain surface functional groups, thermally annealing at different temperatures, and carefully comparing with a series of model compounds. The results illustrate that the superior catalytic performance of GO in the PODE n synthesis should be ascribed to a synergy between the surface sulfonyl, hydroxyl and carboxyl groups present on the GO surface and the unique layered structure of GO sheets, wherein the surface sulfonyl groups act as the main active sites. The insights shown in this work are beneficial to a deep understanding on the catalytic principle of GO and development of efficient catalyst for the synthesis of PODE n .
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2018
·
IF 4.908
Bo Wang,Xiong-Min Liu,Xia-Na Fu,Yuan-Lin Li,Pin-Xian Huang,Qiang Zhang,Wei-Guang Li,Li Ma,Fang Lai,Peng-Fei Wang
In this work, thermal oxidation reaction of dimethoxymethane (DMM) at low temperature was investigated with a custom-designed mini closed pressure vessel test (MCPVT) employed. The initial auto-oxidation, thermal decomposition and deep radical oxidation processes were revealed by analyzing the behavior of oxidation temperature (T) and pressure (P) in the process of MCPVT monitoring. Peroxides generated from DMM auto-oxidation were measured by iodimetry and thin-layer chromatography (TLC). The dominant peroxide was separated from oxidation products via column chromatography, with structure characterized by mass spectrometry (MS), 1 H and 13 C nuclear magnetic resonance (NMR). The thermal decomposition characteristics were determined by differential scanning calorimeter (DSC). Results show that the oxidation was mainly initiated by hydrogen abstraction on the methylenedioxy (O-CH 2 -O) of DMM when temperature was above about 310 K. The primary product of hydroperoxide, hydroperoxy(methoxymethoxy)methane was found in DMM oxidation for the first time, with a high level. Its exothermic onset temperature (T 0 ) and decomposition heat (Q DSC ) are 372.87 K and 2431.37 J·g −1 , respectively. The thermal decomposition could lead to thermal runaway of oxidation, and further transform into an explosion. In most cases, the release of radical pool after peroxides decomposition would induce a rapidly radical oxidation of DMM through an endothermic reaction at about 410 K.
研究领域:
化学工程
·
安全科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2018
·
IF 4.484
Zhiqiang Xie,Congbiao Chen,Bo Hou,Dekui Sun,Heqin Guo,Jungang Wang,Debao Li,Litao Jia
The nature of high-silica H–Y acid sites in dimethoxymethane carbonylation is investigated by NH3 poisoning with a combination of reaction results, diffuse reflection infrared Fourier transform spectra, and NH3 temperature-programmed desorption. After NH3 poisoning of H–Y, ammonia desorption of zeolites NH4–Y was conducted at different temperatures to obtain catalysts HNH4–Y that gradually exposed different acid sites. The zeolites thus produced catalyzed dimethoxymethane carbonylation with a linear dependence of the conversion on the ammonia desorption temperature before the plateau stage. It was observed that strong Brønsted acids in zeolite Y catalyzed the reaction more selectively toward the main product methyl methoxyacetate, and weak Brønsted acids catalyzed the reaction more selectively toward the byproduct methyl formate. Furthermore, the turnover frequency of Brønsted acids varied significantly among the Brønsted acids and decreased with acid strength. This finding suggested that only 10.1–18.3% of the total Al in zeolite Y with Si/Al ratios of 15, 30, and 40 contributed to the total framework Brønsted acids.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2020
·Vol. 34
·期 11
·e5925
·
IF 3.14
Jie Yao,Yan Wang,Suleiman Sabo Bello,Guangwen Xu,Lei Shi
As it is well known, Brønsted acid sites in 8-MR of H-MOR (mordenite) are selective for dimethyl ether (DME) carbonylation to methyl acetate, whereas those in 12-MR are more prone to methanol to olefin reaction. Interestingly, we observed that the Brønsted acid sites in 12-MR of H-MOR are highly active for dimethoxymethane (DMM) carbonylation to methyl methoxyacetate (MMAc), whereas those in 8-MR led to the formation of DME. A series of modified H-MOR catalysts with accurate regulation of Brønsted acid sites in 12-MR or 8-MR were successfully synthesized by selective Na + exchange or pyridine (Py) adsorption. Fourier-transform infrared (FT-IR) spectra, NH 3 -temperature-programmed desorption, Py-FT-IR, and inductively coupled plasma analyses suggested that Na + first occupied Brønsted acid sites in 8-MR and then replaced those in 12-MR. All Na + -exchanged catalysts exhibited significant acceleration on MMAc selectivity, and the ratio of Brønsted acid amount in 12-MR/total had a positive correlation with MMAc selectivity. The MMAc selectivity (78%) of H-MOR-0.15Na was nearly 2.5 times more than that of untreated H-MOR (31%). However, H-MOR-Py showed almost no carbonylation activity (<1% MMAc) and a highest DME selectivity (98%), indicating that Brønsted acid sites in 12-MR were the only active sites for DMM carbonylation, whereas those in 8-MR tended to accelerate DMM disproportionation to DME.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2024
·
IF 5.3
Qilong Fang,Jun Fang,Yi Zhang,Jianguo Zhang,Tianyou Lian,Wei Li,Yuyang Li
Oxymethylene ethers (OMEs) have received great attention due to their carbon-neutral nature and advantageous properties as alternative transportation fuels or fuel additives. Previous studies focused on the combustion of linear OMEs with the chemical formula of CH 3 O(CH 2 O) m CH 3 ( m ≥ 0), while a deep understanding of the combustion of branched OMEs with the chemical formula of CH 3 OCH 3- n (OCH 3 ) n (0 ≤ n ≤ 3) is still absent. In this work, the flow reactor pyrolysis of dimethoxymethane (DMM, n = 1), trimethoxymethane (TMM, n = 2), and tetramethoxymethane (TeMM, n = 3) is investigated using gas chromatography, with special attention given to the multi-sidechain effects on the pyrolysis chemistry. A pyrolysis model of branched OMEs is developed and validated against the new pyrolysis data. Modeling analysis is performed to provide insights into the pyrolysis chemistry of the three branched OMEs and the multi-sidechain effects. Unimolecular decomposition and H-abstraction reactions are found to be two major types of fuel decomposition pathways, with the former dominating TMM decomposition, the latter dominating DMM decomposition, and both contributing almost equally to TeMM decomposition. Sensitivity analysis shows that C O bond dissociation is the most sensitive reaction to fuel decomposition in DMM pyrolysis, while methanol elimination is the most sensitive reaction in TMM and TeMM pyrolysis. Among the three fuels, DMM has the lowest pyrolysis reactivity and produces the least abundant methanol. In contrast, TMM is observed with the highest pyrolysis reactivity and produces the most abundant methanol. Theoretical calculations reveal that TMM and DMM have the lowest and highest energy barriers of methanol elimination reactions, which determines the order of their pyrolysis reactivities and methanol formation trends. As a result, DMM pyrolysis occurs at higher temperature regions where the C O bond dissociation and H-abstraction reactions are preferred, while TMM pyrolysis occurs at lower temperature region where methanol elimination dominates.
研究领域:
能源科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2019
·
IF 0
Chunlei Zhang,Ping Wu,Guojuan Liu,Zhigao Zhu,Gaofeng Zeng
Direct oxidation of methanol to high value oxygenated chemicals on V2O5/TiO2 based catalysts is a green alternative to the commercial methods. But the V–Ti based catalysts are challenged by the relatively low reactivity. Herein, we demonstrated a facile and practicable strategy to directly fabricate hollow structure VOx/TiO2 nanofibers (VTO-HNF) through the coelectrospinning and calcination method. The effects of V/Ti ratio on the structure, the surface chemistry and methanol oxidation performance were investigated in detail. VTO-HNFs with appropriate V/Ti ratio have hierarchical structure, large surface area, uniform nanoparticles, narrowed grain sizes, and high dispersions of vanadium. Moreover, both the oxidation properties and the acidities of the catalyst were enhanced due to the high content of surface V4+. The VTO-HNF catalysts featured excellent activities and reliable stability for the selective oxidation of methanol to methyl formate (MF) and dimethoxymethane (DMM). The MF yield reached 90% at 150 °C, which is comparable with the noble metal based catalysts. In situ NAP-XPS investigations suggested that the variable valence of vanadium was involved in the oxidation of methanol.
研究领域:
材料科学
·
催化
·
化学工程
✓ 已验证
产品关联
DOI
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Xiaoyu Cao,Xiaomin Qiu,Fan Zhang,Meng Xiao,Tingting Huang,Quanhong Zhu,Zhijie Shang,Hongbing Song
The development of affordable, intelligent dual-separation technology is crucial for the treatment of oil–water mixtures. Pyridinium-based poly(ionic liquid)s (PILs), designed using molecular theory, exhibit unique switching wettability properties, making them ideal for use in both aqueous and oily environments. By prewetting the material’s surface with water or oil, the targeted separation of these components becomes feasible. PILs are synthesized through the cross-linking of [Pyr]Cl with various cross-linkers and auxiliary agents. Studies on the wetting mechanism of these materials have identified bursting pressure and surface structure as key factors influencing their wetting properties. They exhibit hydrophilic and lipophilic properties in air, hydrophobic properties under oil, and oleophobic properties under water, achieving a 99% separation efficiency. A reusability study demonstrated maintenance of 90% efficiency after 10 cycles, highlighting their sustained high performance. This research presents promising avenues for the application of PIL-based materials in oil–water separation, environmental remediation, and industrial processing.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
You Shu,De-Xuan Xiang,Man-Ying Li,Xiao-Ru Xie,Qing-Yao Chen,Yi-Ting Lin,Zhi-Yong Yang,Yue-jun Ouyang,Gui Chen
Lignin is an important organic polymer and a potential renewable resource. In this work, two novel palladium immobilized on lignin-based hypercrosslinked polymers were successfully fabricated via the Friedel-Crafts alkylation reaction and metallization. The protocol is associated with mild conditions, low cost, high yield, easy separation. The structure of the catalysts were studied by FT-IR, N 2 sorption, XPS, ICP, TGA, TEM, and SEM. Analysis indicates that the polymers exhibit significant characteristics such as large pore volume, highly distributed palladium, excellent chemical and thermal stability, and high specific surface areas. Subsequently, the heterogeneous catalysts were deployed within the context of the Suzuki-Miyaura reaction as a means to evaluate their catalytic activity. In the realm of aqueous environments, HCP-L&Pd-I showcases remarkable efficiency in catalyzing the Suzuki-Miyaura reaction, which benefited from the synergistic effect between the hierarchical pore structure in the material and numerous hydroxyl groups in lignin coordinating with palladium. Under optimum conditions, 0.1 mol% Pd content was enough to react with 97 % yield of biphenyl. Moreover, the catalyst was simply regenerated and reused six times without significant activity loss. This protocol perhaps provides a new perspective on the effective preparation of biphenyl aromatic compounds utilizing lignin-based heterogeneous catalysts in the Suzuki-Miyaura reaction.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2024
·Vol. 50
·期 5
·2051-2066
·
IF 2.8
Feng Lu,Lu Sihang,Zou Haolei,Chen Gui,Xiang Dexuan
An efficient and stable palladium species catalyst immobilized on functionalized hyper–cross-linked polymers (HCPs-Pd) has been successfully developed and applied in the Suzuki–Miyaura coupling reaction of diverse types of aromatic halides with aryl boronic acid in this work. The results demonstrated that HCPs-Pd exhibited high catalytic activity, which benefited from the microporous structure of the catalyst guaranteed high dispersibility of active palladium, and high specific surface area, large pore volume, good chemical stability. Under optimal reaction conditions, 93.0% of biphenyl yield in the Suzuki–Miyaura reaction with bromobenzene (C 6 H 5 Br) and phenylboronic acid (C 6 H 7 BO 2 ) as raw material was obtained. The good stability of the HCPs-II-Pd catalyst was verified by five cycles experiments. Perhaps this work provides new insights into the high-yield preparation of aromatic biphenyl compounds employing HCPs-Pd as an efficient and stable catalyst in the Suzuki–Miyaura reaction. Graphical abstract
研究领域:
化学
·
材料科学
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）