FUEL
·
2021
·
IF 6.609
Zhi Yang,Bowen Luo,Riyang Shu,Zhipeng Tian,Yu Kang,Ying Chen
An effective binary catalyst by using tungstic acid (H 2 WO 4 ) and Ru/C was employed for the hydrodeoxygenation (HDO) of phenolic compounds and raw lignin-oil. H 2 WO 4 was presented as solid at ambient temperature, but it dissolved at high temperature above 100 °C and therefore functioned as an active homogeneous catalyst. This phenomenon resulted in a temperature-controlled phase-transfer behavior in the HDO of phenolic compounds. An efficient HDO performance and an exceptional reusability for guaiacol HDO were presented by this bifunctional catalyst, which can be reused more than 10 times with guaiacol conversion and cyclohexane selectivity over 90%. The comparison of traditional liquid organic and mineral acids, as well as solid acids, with H 2 WO 4 confirmed the outstanding catalytic performance of H 2 WO 4 and highlighted the advantages of H 2 WO 4 as a homogeneous catalyst. Besides guaiacol, other phenolic compounds including various monomers and dimers all exhibited good HDO results, with 100% conversion and cycloalkanes selectivity. Moreover, the raw lignin-oil can be efficiently deoxygenated under the catalysis of this bifunctional catalyst. 99.3% content of hydrocarbons was obtained in the upgraded lignin-oil, which was promising to be used as fuel directly. This catalytic system has great potential for the industrial application of lignin-oil upgrade.
研究领域:
化学工程
·
可再生能源
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产品关联
DOI
高影响因子
CELLULOSE
·
2019
·Vol. 27
·期 2
·799-823
·
IF 3.917
Lv Wei,Liao Yuhe,Zhu Yuting,Liu Jing,Zhu Changhui,Wang Chenguang,Xu Ying,Zhang Qi,Chen Guanyi,Ma Longlong
The cleavage of linkages of lignocellulose is important for its valorization. The linkage cleavage of cornstalk hydrolysis residue was investigated over catalysts (Ru/C + MgCl 2 ) in EtOAc/H 2 O solvents. The results show that almost hydrogen bonds, C–C bonds, ether and ester bonds in the matrix of lignin and cellulose were broken, accompanying 80.6% of lignin and 98.5% of cellulose conversion, and obtaining 37.5% of aromatic monomers and 28.8% of lignin oligomers. In the reaction system, biphasic EtOAc/H 2 O solvents exhibited an effect on cleaving the intermolecular linkages between lignin and cellulose. MgCl 2 showed limited abilities of breaking the α-O-4 and β-O-4 linkages in lignin and limited β-1, 4-glycosidic and hydrogen bonds in cellulose were cleaved over Ru/C catalyst. The cleavage of C–O linkages (α-O-4, β-O-4, 4-O-5) and C–C bonds (α-β, β-5) in lignin were mainly dependent on Ru/C catalyst. Much C–O and the stubborn C–C linkages of β-5, β-1 and 5-5 were significantly disrupted by the synergistic effect between MgCl 2 and Ru/C. However, MgCl 2 exhibited great contribution to breakage of β-1, 4-glycosidic linkage, hydrogen bonds and sugar ring of cellulose. The linkage of β-1, 4-glycosidic, hydrogen bonds and C–C in C5/C6 sugars were significantly broken. The increased yield of products was evidently due to the synergistic effect of Ru/C combined with MgCl 2 .
研究领域:
生物质化学
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催化化学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 16
·7583-7587
·
IF 3.3
Baole Li,Tiansheng He,Chen Zuo,Zhi Cao,Taihong Yan,Weifang Zheng
Catalytic decomposition of hydrazine nitrate is a very important research topic in the environmental protection field. Herein, we used an Ru/C catalyst for the decomposition of hydrazine nitrate in HNO3, and the reaction kinetics and mechanism were studied in detail. The kinetics study of the decomposition of hydrazine nitrate (0.01 M) was conducted in the temperature range 313–343 K in 0.1 M HNO3 in the presence of Ru/C. The apparent activation energy for this reaction was 46.6 kJ mol−1 according to a fitting of the experimental data, while the reaction order was 1.5. It was also found that the reaction pathway of the catalytic decomposition of hydrazine nitrate on the Ru/C catalyst involved two processes: heterogeneous catalytic disproportionation of hydrazine nitrate at the catalyst surface and oxidation of hydrazine nitrate with catalytically generated HNO2.
研究领域:
环境科学
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催化化学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2021
·
IF 5.706
Weizhen Xie,Huai Liu,Xing Tang,Xianhai Zeng,Yong Sun,Xixian Ke,Tianyuan Li,Huayu Fang,Lu Lin
The catalytic conversion of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), a renewably sourced substitution for petroleum-derived terephthalic acid, at a high concentration is highly demanding but challenging. Herein, the efficient conversion of HMF (10–25 wt%) in 1,4-dioxane/H 2 O was achieved, and a desirable FDCA yield of 98% was obtained from HMF (10 wt%) over commercial Ru/C (2 Equiv. NaHCO 3 , 4 MPa O 2 , 3 h, and 140 ℃). In addition, a two-step cascade reaction was developed for FDCA production, in which FDCA was employed as the acid catalyst to promote the dehydration of fructose (10 wt%) to HMF, followed by oxidation in 1,4-dioxane/H 2 O to FDCA over Ru/C. As compared to pure water or 1,4-dioxane, the better stability of HMF in 1,4-dioxane/H 2 O with a weak alkaline environment and the enhancement of superoxide radicals (·O 2 - ) in 1,4-dioxane/H 2 O could ensure high FDCA yield at high HMF concentration.
研究领域:
化学工程
·
可再生资源化学
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催化化学
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产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2017
·
IF 5.951
Wei Lv,Zhan Si,Zhipeng Tian,Chenguang Wang,Qi Zhang,Ying Xu,Tiejun Wang,Longlong Ma
An EtOAc/H2O biphasic solvent–Ru/C coupling biorefinery process was developed to selectively produce aromatics from cornstalk hydrolysis residue (CHR). In this process, CHR was depolymerized in an ethyl acetate (EtOAc)/H2O biphasic solvent system over Ru/C catalyst, which produced aromatics and carbohydrates instantly separated by EtOAc and H2O. Most lignin in CHR was converted to aromatics and nonvolatile fractions, accompanied with partial degradation of cellulose. Optimized results showed that more than 42.7% of aromatics can be obtained under 260 °C for 5 h without external hydrogen pressure. Monophasic and biphasic parallel experimental results show that the strong lignin dissolving ability of the biphasic dissolution/separation system is helpful for aromatics production and separation, which promoted CHR depolymerization over Ru/C. Furthermore, CHR, products, depolymeirzation residue solid (DRS), and catalysts were carefully characterized by gas chromatography (GC-MS), Fourier transform infrared (FT-IR), gel permeation chromatrography (GPC), high-performance liquid chromatrography mass spectrometry (HPLC-MS), nuclear magnetic resonance (NMR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis. Results demonstrated that the biphasic solvent–Ru/C coupling process can significantly alleviate repolymerization reactions. Based on these analysis results, the catalytic process in biphasic EtOAc/H2O was discussed. This work demonstrates that such a green biphasic catalytic/separation coupling system highlights a promising route for efficient biomass degradation and product separation at mild conditions without external hydrogen pressure.
研究领域:
生物化学
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可再生能源
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DOI
高影响因子
Journal of Physical Chemistry C
·
2023
·
IF 3.7
Jia-Qi Chen,Xu-Xu Ye,Da Zhou,Yan-Xia Chen
Electrochemical reduction is a potential solution to eliminate nitrate in wastewater; however, the poor activity and product selectivity of traditional electrocatalysts impede its large-scale application. Herein, we report a new catalyst of Cu-modified Ru nanoparticles (Cu-modified Ru/C NPs) prepared by underpotential deposition (UPD) of Cu atoms onto Ru NPs, which shows good nitrate reduction kinetics and NH3 selectivity. To unravel the enhancing mechanism, the impact of Cu coverage on nitrate reduction and the formation of possible products/intermediates as well as the competition of side products H2 have been investigated systematically by tracking the reverse oxidation of such species using rotation ring disk electrode (RRDE) combined with cyclic voltammetry. Our results reveal that the Cu-modified Ru/C NPs perform NH3 yield of 23.7 μmol h–1 cm–2 and 95% Faradaic efficiency, which is better than Ru/C NPs (6.0 μmol h–1 cm–2 with Faradaic efficiency of 66%); This enhancement of modified Cu atoms toward nitrate reduction results from synergetic effects: (i) Cu blocks the hydrogen evolution reaction (HER) sites on Ru surface; (ii) Cu accelerates the rate of nitrate reduction to nitrite; (iii) the enhanced nitrite reduction activity of Cu sites on Ru substrate is probably a result of changes in electronic structure of Cu.
研究领域:
环境科学
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催化
·
电化学
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产品关联
DOI
高影响因子
FUEL
·
2015
·
IF 3.52
Yujing Weng,Songbai Qiu,Chenguang Wang,Lungang Chen,Zhengqiu Yuan,Mingyue Ding,Qi Zhang,Longlong Ma,Tiejun Wang
In this work, a dual-bed aqueous catalysis system with Ru/C as catalyst was proposed for the liquid alkane (pentane/hexane: C5/C6) production from acid biomass hydrolysate. The low temperature (413 K) hydrogenation of biomass-derived carbohydrates into polyols was carried out in the first fixed-bed. The high temperature (523 K) hydrodeoxygenation (HDO) of polyols into alkanes was carried out in the down-stream bed. To screen the optimal reaction conditions, glucose and sorbitol were chosen for model tests. Whereby, reactor types, solution pH value, mineral acid, reaction temperature, pressure and sorbitol concentrations were studied. A maximum C5/C6 alkane yield of 61.9% was achieved from 20 wt% sorbitol solution (pH = 1.5) under 523 K and 4 MPa H 2 pressure in the fixed-bed reactor. For cassava and corncob hydrolysate, C5/C6 alkane yield of 38.8% and 44.1% were obtained, respectively.
研究领域:
化学工程
·
可再生能源
·
催化
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Bioengineering and Biotechnology
·
2022
·
IF 6.064
Shao Lupeng,Wang Chao,Liu Yu,Wang Meng,Wang Luyan,Xu Feng
Lignin, an abundant aromatic biopolymer, has the potential to produce various biofuels and chemicals through biorefinery activities and is expected to benefit the future circular economy. Microwave-assisted efficient degradation of lignin in methanol/formic acid over Ru/C catalyst cooperated with metal chloride was investigated, concerning the effect of type and dosage of metal chloride, dosage of Ru/C, reaction temperature, and reaction time on depolymerized product yield and distribution. Results showed that 91.1 wt% yield of bio-oil including 13.4 wt% monomers was obtained under the optimum condition. Yields of guaiacol-type compounds and 2,3-dihydrobenzofuran were promoted in the presence of ZnCl2. Formic acid played two roles: (1) acid-catalyzed cleavage of linkages; (2) acted as an in situ hydrogen donor for hydrodeoxygenation in the presence of Ru/C. A possible mechanism for lignin degradation was proposed. This work will provide a beneficial approach for efficient depolymerization of lignin and controllable product distribution.
研究领域:
化学工程
·
生物化学工程
·
催化
·
可再生能源
✓ 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）