FUEL
·
2017
·
IF 4.601
Ting Lu,Yucui Hou,Weize Wu,Muge Niu,Shuhang Ren,Zengqi Lin,Vijay K. Ramani
The transformation of biomass into platform chemicals is a key intermediate step to establish biomass-based sustainable chemical processes. The preparation of oxygenated chemicals by conversion of biomass is of significant conceptual and practical interest. In this work, an efficient catalytic system for carbohydrate-based biomass oxidation to oxygenated chemicals (including formic acid, dimethoxymethane and methyl formate) with O 2 using H 5 PV 2 Mo 10 O 40 as catalyst is presented. Conversions of glucose and cellulose in a methanol/water medium achieved total product yields of oxygenated chemicals up to 92.9% and 89.7%, respectively (based on carbon). A conversion pathway to clarify the mechanism of product formation was proposed. Protecting reactive functional groups of sugars and reaction intermediates via acetalisation and etherification in methanol effectively suppressed CO 2 formation and remarkably enhanced the production of oxygenated chemicals. The effect of solvent composition on catalyst H 5 PV 2 Mo 10 O 40 was investigated, and it was found that the structural stability of the catalyst increased by the addition of methanol. The catalyst was reused four times without significant decline in activity.
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
DALTON TRANSACTIONS
·
2018
·Vol. 47
·期 18
·6394-6403
·
IF 4.099
Yanqin Li,Qi Gao,Lijuan Zhang,Yunshan Zhou,Yuxu Zhong,Ying Ying,Mingcai Zhang,Chunqian Huang,Yong'an Wang
Currently extensive effort is compulsively expended to decontaminate efficiently banned chemical war agents. In this work, H5PV2Mo10O40 molecules have been encapsulated in mesoporous MIL-101(Cr), which features two types of mesoporous cages (internal diameters of 29 Å and 34 Å) and microporous windows (diameters of 12 Å and 16 Å), leading to the formation of a new composite H5PV2Mo10O40@MIL-101(Cr) through a simple impregnation method. The composite was characterized thoroughly by elemental analysis, FT-IR spectroscopy, powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, TG/DTA, and textural analysis thereby confirming the encapsulation of the H5PV2Mo10O40 into MIL-101(Cr). The decontamination efficiency of sulfur mustard (4 μL HD in 40 μL of petroleum ether) by 20 mg of the composite is found to be 97.39% in 120 min under ambient conditions. GC-MS analysis on the decontaminated products using 2-chloroethyl ethyl sulfide (CEES), which has been widely used as a simulant of sulfur mustard, showed that MIL-101(Cr) just decontaminates CEES by adsorption, while CEES can be decontaminated under ambient conditions by a synergetic combination of adsorption of MIL-101(Cr) and subsequent chemical oxidation degradation to nontoxic 2-chloroethyl ethyl sulfoxide (CEESO) due to the presence of highly dispersed H5PV2Mo10O40 within the composites.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2017
·
IF 3.091
Fan Yang,Yucui Hou,Muge Niu,Ting Lu,Weize Wu,Zhenyu Liu
Carboxylic acids (CAs) are considered as an important group of chemicals and are widely used in the chemical industry. The production of CAs via oxidation of lignite is a promising industrial process. In the present work, we found that H5PV2Mo10O40 (HPA) was beneficial to catalytic oxidation of lignite by O2 in aqueous H2SO4 solutions to produce CAs. The effects of HPA concentration, H2SO4 concentration, reaction temperature, initial O2 pressure, and reaction time on lignite conversion and CA yield were studied. The catalytic oxidation of lignite in aqueous HPA/H2SO4 solutions with O2 can yield 56.9 wt % CAs, including 33.5 wt % formic acid, 14.4 wt % acetic acid, 1.5 wt % succinic acid, 1.1 wt % oxalic acid, and 6.4 wt % benzene carboxylic acids (BCAs, including 12 types) at 170 °C and 3 MPa for 60 min. In this catalyst system, the existence of H2SO4 can change the catalytic activity of HPA, and the synergistic effect of HPA and H2SO4 can significantly promote the production of CAs. VV can oxidize lignite or intermediates to form VIV, which can be reoxidized by O2 to complete a redox cycle. In the catalytic oxidation, lignite was converted into water-soluble intermediates at first, and then the water-soluble intermediates were converted to CAs. The catalyst system was reused four times without significant decline in activity. Compared with the traditional alkali-oxygen oxidation, this method can decrease the usage of mineral acid and alkali and lower reaction temperatures.
研究领域:
能源化学
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工业催化
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环境化学
·
有机化学
·
资源利用
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2016
·Vol. 18
·期 17
·4725-4732
·
IF 8.506
Ting Lu,Muge Niu,Yucui Hou,Weize Wu,Shuhang Ren,Fan Yang
The preparation of formic acid (FA) by catalytic oxidation of sustainable biomass is of significant conceptual and practical interest, because FA is an important chemical and is now produced from non-sustainable fossil fuel. In this work, we found that a binary catalyst of Keggin-type heteropoly acid H5PV2Mo10O40 + H2SO4 was efficient in oxidizing biomass cellulose to FA using oxygen as an oxidant in aqueous solution. In the oxidation, the pH of the aqueous solutions plays a key role, and a decrease in pH improves the transformation. Cellulose was transformed to FA with conversions from 60% to 100% and FA yields from 28% to 61% (based on the carbon atoms in the feedstock) after 5 min of reaction at 180 °C, using H2SO4 as an additive to decrease the pH from 1.79 to 0.56. The influences of the pH on both the catalyst and the reaction pathway were discussed. By decreasing the pH, the oxidation potential and electron affinity were increased due to the formation of protonated H5PV2Mo10O40 and VO2+ species, favoring the reduction of the catalyst and oxidation of the substrate. A reaction pathway for the generation of products was proposed, and the influence of the pH on the reaction pathway was also discussed.
研究领域:
化学工程
·
生物质能
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Xing Wei,Qingqiang Wang,Xunli Zhang,Ying Chen,Nan Jin,Yuchao Zhao
The process of converting glucose into formic acid (FA) has been explored as a promising route for using biomass as a renewable feedstock for green chemical manufacturing. However, the most commonly used batch-tank reactor systems currently suffer from several drawbacks, including extended processing time, limited product selectivity, and high energy consumption, while the underlying reaction paths have been poorly understood. In this work, a continuous flow microchannel reactor was employed for the glucose conversion catalyzed by H 5 PV 2 Mo 10 O 40 with O 2 as an oxidant. The influence of various parameters on the conversion rate of glucose and the FA yield was characterized. Experimental results indicated that with a residence time of less than 3 min, the glucose was completely converted, and the highest FA yield reached 82.40 %. Extensive examination on the apparent by-products revealed that most of them acted as intermediates to produce FA through various pathways, including glyoxal, glyceraldehyde and glycolaldehyde as key intermediates for the oxidation of glucose to FA. Furthermore, the density functional theory (DFT) method was used to determine the bond energies of different C–C bond cleavage modes of substrate glucose and fructose produced by the isomerization of glucose. Experimentally, the conversion of three main intermediates and some other possible intermediates and their FA yield were measured with different residence time. It was also found that the CO 2 was produced through the decarboxylation of α-hydroxy and α-carbonyl carboxylic acid compounds, while the aldehyde groups in the compounds were more likely converted to FA by the α-carbon bond cleavage. Finally, plausible reaction pathways were proposed for the process of glucose-to-FA catalyzed by HPA-2, providing useful guidance for the identification of side reaction pathways and further improvement of FA yield.
研究领域:
化学工程
·
绿色化学
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催化
·
反应工程
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2021
·
IF 5.455
Yupeng Zhai,Jialin Yu,Lijuan Zhang,Yunshan Zhou,Yuxu Zhong,Ying Yang,Yong’An Wang
In this study, an α-Keggin-type polyoxometalate H 5 PV 2 Mo 10 O 40 was loaded into the adamantane cage (18 Å) of MOF-808(Ce) by an immersion method to obtain composites with different polyoxometalate loadings. The effects of the H 5 PV 2 Mo 10 O 40 loading in the composite, the reaction time, and the quantity of the composite during the decontamination of the erosive agent surrogate, 2-chloroethyl ethyl sulfide (CEES) were investigated, and the optimized catalytic conditions for CEES were determined. The decontamination rate of 4 μL CEES reached 93.91% in 120 min using 40 mg of optimized composite, and the decontamination rate of 160 μL of the nerve agent surrogate, methyl paraoxon (DMNP) reached 100% in 25 min using 5 mg of the composite. Decontamination of CEES and DMNP by the composite followed first-order reaction kinetics. The half-life ( t 1/2 ) and kinetic rate constant ( k ) of these two reactions were 27.77 min and −0.02496 min −1 and 1.895 min and −0.36569 min −1 , respectively. The composite exhibited good decontamination performance after four replicate experiments. The results showed that CEES was oxidized to CEESO, while DMNP was hydrolyzed to p -nitrophenol and dimethyl phosphonate in the presence of the composite, showing that the proposed composite is an effective bifunctional catalyst for the selective oxidation and hydrolysis of chemical warfare agent surrogates.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）