ACS Omega
·
2020
·
IF 2.87
Zheng Shen,Yishan Gao,Ling Kong,Minyan Gu,Meng Xia,Wenjie Dong,Wei Zhang,Xuefei Zhou,Yalei Zhang
Amine-modified Sn-β was synthesized to improve the yield of lactic acid produced from Scenedesmus. After studying the growth of Scenedesmus, we selected Scenedesmus with the highest sugar content of 46.7% after 8 days of culture as the reaction substrate. The results showed that the yield of lactic acid from Scenedesmus was greatly increased after being catalyzed by 3-aminopropyltrimethoxysilane (APTMS)-modified Sn-β. After the pretreatment of Scenedesmus in an ice bath ultrasound, under the optimal reaction conditions (190 °C and 5 h), the yield of lactic acid reached the highest (37%). The acid–base characterization results of the catalyst confirmed that there are both Lewis acidic sites and medium-strength basic sites in the catalyst. Both of these sites can promote the hydrolysis of Scenedesmus, while the Lewis acidic sites can promote the production of lactic acid and the basic sites can effectively inhibit the production of the byproduct 5-hydroxymethylfurfural (HMF). This study proved that this amination catalyst is a useful strategy to increase the yield of lactic acid.
研究领域:
生物化学
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催化化学
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环境科学
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产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Xiaomei Yang,Jie Hu,Tianliang Lu,Lipeng Zhou
Sucrose is an abundant, cheap and sustainable substrate for producing high value-added chemicals. In this work, the role of weak Brønsted (B) acid site of Sn-β zeolite was revealed in sucrose conversion to methyl lactate (MLA). Sn-β zeolites were prepared by post-synthesis and hydrothermal synthesis in F ‒ media and modified by Mg 2+ to tune the B acidity. The acidity of the zeolites was characterized by FT-IR spectroscopy of pyridine/CD 3 CN adsorption and hydroxyl region. Their catalytic performance for sucrose conversion to MLA in methanol indicates that weak B acid sites of silanols are indispensible for breaking the glycosidic bond of sucrose, so the highest MLA yield was obtained over the postsynthesized Mg-Sn-β-P with moderate amount of weak B acid sites of silanols, strong L acid sites and no strong B acid sites, which juggled the alcoholysis/hydrolysis of sucrose and the retro-aldol of C 6 monosaccharide to MLA, and at the same time inhibited the dehydration side-reaction.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2025
·
IF 9.1
Yingfu Tian,Tianliang Lu,Hongjin Qu,Xiaomei Yang,Lipeng Zhou
Efficient conversion of ethyl levulinate (EL) in high concentration to γ-valerolactone (GVL) at moderate temperature via catalytic transfer hydrogenation strategy is highly desirable. In this work, hydrothermally synthesized Sn-β zeolite with high Sn content was employed as a catalyst to realize this aim. Fully crystallized Sn-β zeolite with high Sn content ( n Si / n Sn = 60) was successfully synthesized within 12 days using MgCl 2 as a promoter. The synthesized zeolites were characterized by XRD, SEM, UV-vis spectroscopy, FT-IR spectroscopy and XPS. The L acid density of Mg-Sn-β-60-12d increased to 90 μmol g −1 compared to Mg-Sn-β-100-7d (56 μmol g −1 ). 92% yield of GVL was achieved on Mg-Sn-β-60-12d using high concentration of EL (1.2 mol L –1 ) as reactant at 130 o C for 8 h. The performance of Mg-Sn-β is better than that of Sn-β with same n Si / n Sn . The reaction mechanism over Mg-Sn-β was discussed. In addition, Mg-Sn-β-60-12d showed excellent stability and reusability during five runs.
研究领域:
化学工程
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催化材料科学
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2020
·Vol. 10
·期 9
·2986-2993
·
IF 5.721
Wenda Hu,Zixin Chi,Yan Wan,Shuai Wang,Jingdong Lin,Shaolong Wan,Yong Wang
This work presents a novel method to selectively convert levoglucosan to lactic acid (LA) via initially adding LA as the Brønsted acid together with modified Sn-β as the Lewis acid. Sn-β catalysts exchanged with various cations significantly enhance the yield of LA, following the order Sn-β < Sn-β–Na < Sn-β–K < Sn-β–Mg, Sn-β–Ca. The role of exchanged alkali ions stems from removing the remaining Brønsted acid sites in the zeolite and tuning the framework oxygen with more Lewis base sites. The exchange with alkaline earth cations such as Ca2+ and Mg2+ appears to be more effective in promoting the retro-aldol condensation due to the synergetic effect of their stronger Lewis acid that can stabilize the oxygen atom of deprotonated alkoxides during the reaction. The LA yield from levoglucosan can reach up to 66% on Sn-β–Ca under the optimized conditions. We also demonstrated that such a synergetic effect of alkaline-earth ion exchanged Sn-β shows great universality toward enhanced retro-aldol condensation, which can significantly promote the yield of methyl lactate over glucose conversion in methanol solvent.
研究领域:
催化化学
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生物质转化
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绿色化学
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产品关联
DOI
高影响因子
Energy Technology
·
2016
·Vol. 5
·期 5
·747-755
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IF 2.557
Tingwei Zhang,Wei Fan,Wenzhi Li,Zhiping Xu,Haosheng Xin,Mingxue Su,Yijuan Lu,Longlong Ma
Sn-β zeolite and PTSA–POM, made from the copolymerization of p -toluenesulfonic acid (PTSA) and paraformaldehyde (POM), were used for the production of 5-(hydroxymethyl)furfural (HMF) from glucose in an environmentally friendly solvent system including γ-valerolactone (GVL) and H 2 O. The effects of reaction temperature, reaction time, solvent, and catalyst-to-reactant ratio on the production of HMF were investigated. The combination of the Brønsted acid and Lewis acid catalysts largely improved the catalytic system and resulted in the production of HMF in 60.1 % yield at 140 °C in 30 min. The presence of water in the solvent had a positive influence on the production of HMF from glucose. The combination of the two catalysts also improved the catalytic performance for the production of HMF from cellulose and corn stalk.
研究领域:
化学工程
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可再生资源转化
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
ChemSusChem
·
2025
·
IF 6.6
Hailu Liu,Jianying Lin,Qiyu Liu,Yuhe Liao,Qiaozhi Ma
Graphical In this study, a typical Lewis acid Sn-β with low B/L ratio were synthesized and used for one-pot conversion of cellulose into 5-HMF in MSH/acetone system. The addition of Sn-β acid compensates for the Lewis acidity deficiency of MSH and efficiently promoted 5-HMF selectivity. Under the optimized reaction condition, a high 66.88 % yield of 5-HMF was obtained from cellulose conversion. The catalyst maintained a stable 5-HMF conversion rate after three cycles, achieving a direct conversion of cellulose to 5-HMF with excellent industrial application prospects. Producing 5-hydroxymethylfurfural (5-HMF) from abundant and renewable cellulose is a practical method for lignocellulosic biomass valorization. Nonetheless, the high crystallinity of cellulose restricts the accessibility of catalysts, and the complex reaction pathway generally results in the formation of intermediate by-products and 5-HMF degradation. Molten salt hydrates (MSHs) are unique in dissolving crystalline cellulose and their weak Brønsted acidity can facilitate cellulose hydrolysis to glucose. In this work, one-pot conversion of cellulose into 5-HMF was carried out in LiBr MSHs/acetone biphasic system. The solid acid, Sn-β, was used in the conversion to compensate for the shortages of MSH Lewis acidity. Under the optimized reaction condition at 180 °C for 20 min, a high 5-HMF yield of 66.88 % was obtained from cellulose conversion. The influences of reaction conditions on 5-HMF production were studied, and the synergistic effects of solvents and solid acid were established. The catalyzed can be readily recycled and regenerated via calcination. This technique provides a theoretical foundation and technical basis for constructing a one-step conversion of commercial cellulose to value-added 5-HMF, which proposes significant effects on lignocellulose valorization.
研究领域:
生物质转化
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催化化学
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可再生资源利用
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产品关联
DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2019
·Vol. 150
·期 6
·1641-1649
·
IF 2.372
Luo Qianqian,Lu Tianliang,Xu Jun,Yang Xiaomei,Zhou Lipeng
Abstract Methyl pyruvate (MPA) was synthesized from dihydroxyacetone (DHA), the oxidation product of glycerol, over Sn-β and TS-1 hybrid molecular sieves at low temperature. Sn-β and TS-1 provide the active sites for conversion of DHA to methyl lactate (MLA) and oxidation of MLA to MPA, respectively. Synergism of Lewis acid sites on Sn-β and TS-1 realize the production of MPA from DHA. After optimization, 71% yield of MPA can be obtained under 50 °C. This is the first report for the synthesis of MPA from DHA directly. Graphic Abstract
研究领域:
催化
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绿色化学
·
化工
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产品关联
DOI
高影响因子
ChemSusChem
·
2017
·Vol. 10
·期 23
·4715-4724
·
IF 7.226
Wenda Hu,Yan Wan,Lili Zhu,Xiaojie Cheng,Shaolong Wan,Jingdong Lin,Yong Wang
Graphical Mal to Mol and Dal ! Methylallyl alcohol and diethyl acetal are synthesized from methacrolein by using different Sn-modified Beta zeolites (Sn-β) as catalysts. The Sn-β precalcined in Ar followed by sodium-exchange exhibited the highest selectivity toward the desired products. The possible reaction pathways of the reaction between α,β-unsaturated aldehydes and primary alcohols were investigated and proposed. A new strategy was developed to simultaneously produce two important chemicals, namely, methallyl alcohol (Mol) and diethyl acetal (Dal) from methacrolein in ethanol solvent at low temperature with the use of Beta zeolites modified by tin (Sn-β catalysts). All the Sn-β catalysts were prepared by the solid-state ion-exchange method, wherein the calcination step was conducted under different gas atmospheres. The catalyst precalcined in Ar (Sn-β-Ar) had a reduced number of extra-framework Sn species and enabled more Sn species to be exchanged into the framework as isolated tetrahedral Sn IV , enhancing the catalytic activity of the Meerwein–Ponndorf–Verley (MPV) reaction. The sodium-exchanged Sn-β-Ar, with a reduced number of weak Brønsted acid sites, led to an even better selectivity for Mol, owing to the restriction of the side reactions such as acetalization, addition, and etherification. Under optimized catalyst and reaction conditions, the yield of Mol and Dal reached approximately 90 % and 96 %, respectively. The possible reaction pathways, along with a complex network of side products, was proposed after a detailed investigation through the use of different substrates as reactants. The fine-tuning of Sn-β catalysts through different treatments discussed in this work is of great significance toward the understanding and manipulation of complex reactions between α,β-unsaturated aldehydes and primary alcohols.
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
PubMed
高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Hu Yanru,Zhang Gengrui,Liu Lele,Chi ZiXin,Wang Shuai,Lin Jingdong,Xiong Haifeng,Wan Shaolong
The thermocatalytic conversion of hexose into valuable chemicals such as methyl lactate under mild conditions is very appealing. Here, we report that Mo, Mg co-modified Sn-β catalyst can effectively catalyze the transformation of glucose and fructose into alkyl lactate at moderate temperatures. A maximum yield of around 35% of methyl lactate was achieved from the conversion of glucose in methanol at 100°C over Sn-β catalyst modified with 3 wt% Mo and 0.5 wt% Mg. However, up to 82.8% yield of ethyl lactate was obtained in the case of fructose in ethanol upon the same catalytic condition, suggesting a significant solvent effect. The Mo species plays a key role to enable the retro-aldol condensation of fructose, in which the competing side reactions are significantly suppressed with the assistance of neighboring Mg species probably through a synergetic effect of Lewis acid-base.
研究领域:
催化化学
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绿色化学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 16
·8965-8975
·
IF 2.936
Meng Xia,Wenjie Dong,Minyan Gu,Cheng Chang,Zheng Shen,Yalei Zhang
An experimental study was carried out to convert carbohydrates using bimetal modified beta zeolite to obtain a maximum yield of lactic acid. The relationship between the properties and the catalytic performance of various bimetal modified beta zeolites was evaluated. The results showed that the maximum yield of lactic acid reached 52% with more than 99% glucose conversion over Pb–Sn-beta (0.3 mmol g−1, Pb/Sn = 4 : 7) at 190 °C for 2 h under ambient air pressure. To evaluate the synergetic mechanism of lead and tin, key intermediates such as fructose, dihydroxyacetone, glyceraldehyde and pyruvaldehyde were used as probe reactants that were catalyzed by Pb-beta, Sn-beta and Pb–Sn-beta. The revealed key role of lead was to promote the isomerization of glucose to fructose and the retro-aldol condensation reaction from fructose to dihydroxyacetone and glyceraldehyde; meanwhile, tin had a superior catalytic performance in the dehydration of dihydroxyacetone, the hydration of pyruvaldehyde and the isomerization of pyruvic aldehyde hydrate.
研究领域:
催化
·
化学工程
·
生物质转化
·
材料科学
✓ 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）