JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2024
·
IF 5.8
Yang-Yang Xu,Xing Fan,Feng-Yun Ma,Hai-Xu Zou,Xian-Yong Wei
Directly converting lignite into arenes as commodity chemicals and drop-in fuels is a highly desirable target for researchers. However, this is severely limited by the presence of stable inter unit C-O linkages in lignite. Herein, a highly active catalyst, Co-MoS 2 , has been designed and prepared to be used for the selective catalytic cleavage of inter unit C-O bridged bonds (BBs) in the conversion of Naomaohu (NMH), a lignite, to yield arenes. Both catalytic hydrogenation conversion (CHC) and thermal dissolution (a non-catalytic process, named NCHC) of NMH were conducted using n-hexane as the solvent. The soluble fractions from the first stage of NCHC (SF NCHC-1 ) and CHC (SF CHC-1 ), as well as the second stage of NCHC (SF NCHC-2 ) and CHC (SF CHC-2 ) were obtained using the same solvent. After the first-stage catalytic treatment, the relative contents of arenes and alkanes in SF CHC-1 increased by 16.7 % and 9.3 %, respectively, compared to those in SF NCHC-1 , and the relative content of oxygen-containing compounds (OCCs), such as alcohols, phenols , esters, ketones , acids, and furans, decreased by 13.2 %. For the second-stage conversion, the relative contents of arenes and alkanes in SF CHC-2 were 53.5 % and 15.5 % higher than those in SF NCHC-2 , and the relative contents of OCCs was only 6.6 % in SF CHC-2 . The catalytic mechanisms of cleavage of C-O BBs and deoxygenation were proposed based on the CHC of model compounds and density functional theory (DFT) calculation. The adsorption of OCCs and the activation of released hydrogen radical (H·) by Co-MoS 2 , followed by H· addition to the carbon atom connected to oxygen in C-O BBs and oxygen-containing functional groups, are crucial for the cleavage of C-O BBs and formation of deoxygenated compounds, particularly arenes.
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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Chuhan Zhang,Yanchang Chu,Linying Fu,Qiuyue Wang,Rui Ma,Donghai Xu,Le Yang
Lignin, a renewable resource rich in aromatic ring structures in nature, is an ideal natural source to produce aromatic compounds and cycloparaffin. Herein, we prepare MOF-derived Ni–MoxC/C and Co–MoxC/C as catalysts for the depolymerization of lignin and dimeric model compounds. Diphenyl ether (DPE) with 4-O-5 bond, benzyl phenyl ether (BPE) with α-O-4, and phenethyl phenyl ether (PPE) with β-O-4 are chosen as dimeric model compounds. Overall, Ni–MoxC/C and Co–MoxC/C show distinguished different activity toward product distribution. Ni–MoxC/C facilitates both C–O bond cleavage and hydrogenation of the benzene ring, and the main products are ethyl cyclohexane and cyclohexanol for all three model compounds. In contrast, Co–MoxC/C only facilitates C–O bond cleavage and obtains phenol and ethylbenzene as products. Similarly, for the depolymerization of lignin, cycloparaffins are obtained on Ni–MoxC/C, while phenol, guaiacol, 2,6-dimethoxyphenol, and their respective derivatives are obtained on Co–MoxC/C.
研究领域:
化学工程
·
可再生资源利用
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Yuqaio Ma,Xinping Ouyang,Lisha Zhao,Lifeng Li,Xueqing Qiu
The lignin-first strategy is a crucial approach for highly efficient depolymerization of lignin to produce aromatic monomers as the condensation of lignin occurred during the separating process which increased the difficulty in depolymerization. In this work, a cobalt atom clusters supported on nitrogen-doped carbon catalysts (Co/NC-15) was prepared by adjusting the dosage of melamine to control the morphology, structure, and pyridinic nitrogen content of the catalysts. DFT calculations based on lignin model showed that the doping of nitrogen increased the adsorption energy of the lignin on the supports and decreased the dissociation energy of C-O bonds. Under lignin first strategy, Co/NC-15 exhibited good ability to break C-O bonds at 220 °C of mild condition, in which 84.32 wt% of lignin in lignocellulosic biomass was converted into 40.62 wt% of aromatic monomers, while 84.02 wt% of cellulose was preserved. The atom clusters Co/NC-15 exhibited good catalytic activity to lignin depolymerization due to efficient cleavage of C-O bonds, and hence showed the promising prospect in potential industrial application.
研究领域:
生物化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL RESEARCH
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2021
·
IF 0.782
Chun-Jing Li
We report a direct cross-coupling reaction between (het)aryl pivalates/tosylates and di(het)arylzinc species in 2-methyltetrahydrofuran/N-methyl pyrrolidone (1:1), which occurs via C–O bond cleavage under microwave irradiation. The reaction takes place smoothly in short reaction times without the addition of any catalyst or ligand. The reaction is suitable for a broad scope of substrates and exhibits good functional group compatibility, utilizes a simple work-up procedure, and gives the desired products in high purity.
研究领域:
有机化学
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合成化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
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2023
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IF 3.6
Benqiang Cui,Ye Tian,Yongchao Gao,Shaoyi Hua,Yanhui Shi,Changsheng Cao
Direct introduction of silyl radicals to forge C–Si bonds is of central importance in organic synthesis, owing to the formidable potential of silyl groups as coupling partners for further derivatization reactions to achieve more valuable compounds. Cleavage of heteroaromatic endocyclic carbon–heteroatom bonds to assemble C–Si bonds is scarce. Here, we demonstrate a dearomatization silylation of benzofurans and furopyridines via silyl radical addition and C(2)–O bond scission under metal-catalyst-free and mild conditions. Preliminary mechanistic experiments suggest that these transformations involve radical/single-electron transfer and [1,5]-Brook rearrangement processes. This protocol for the total synthesis of Doxepin and oxyresveratrol derivatives is carried out. The silylated products in several transformation reactions have proven to be useful as synthetic intermediates.
研究领域:
有机化学
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药物化学
✓ 已验证
DOI
PubMed
高影响因子
CATALYSIS COMMUNICATIONS
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2013
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IF 2.915
Shuai Leng,Xinde Wang,Xiaobo He,Lin Liu,Yue'e Liu,Xing Zhong,Guilin Zhuang,Jian-guo Wang
NiFe bimetallic catalyst shows an excellent activity and selectivity for the hydrodeoxygenation (HDO) of three typical model compounds of bio-oil. The conversion of furfuryl alcohol, benzene alcohol and ethyl oenanthate is 100, 95.48 and 97.89% at 400 °C and the yield to 2-methylfuran, toluene and heptane is 98.85, 93.49 and 96.11% at 0.1 ml/min flow speed and atmospheric pressure. It indicates that the major reaction pathway is the cleavage of C–O rather than C–C. After the catalytic HDO of bio-oil over NiFe/Al 2 O 3 catalyst, the heating value changes from 37.8 to 43.9 MJ/kg, the pH changes from 6.65 to 7.50.
研究领域:
能源化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2021
·Vol. 11
·期 9
·3241-3250
·
IF 6.119
Ming Jiang,Xiaopeng Chen,Linlin Wang,Jiezhen Liang,Xiaojie Wei
Selective hydrogenolysis of aryl ethers to produce aromatic compounds is a key strategy for lignin valorization. The use of non-noble-metal catalysts to realize the cleavage of C–O ether bonds under mild conditions has been of considerable research interest recently. We herein report the synthesis of a nitrogen-doped porous-carbon-skeleton-supported Ni–CeO2 catalyst (Ni–CeO2/CN). The synergistic effect between Ni and CeO2 species led to the Ni–CeO2/CN catalyst having a high activity and selectivity for the cleavage of C–O ether bonds at a low reaction temperature. In particular, the Ni–CeO2/CN catalyst showed excellent effectiveness in the hydrogenolysis of benzyl phenyl ether (α-O-4 bonds), and the full conversion was achieved after 2 h at a temperature of 60 °C, with phenol and toluene as the sole reaction products. In addition, the conversion of more robust β-O-4 ether bonds in 2-phenoxy-1-phenylethanol reached up to 100% with the yield of ethylbenzene and phenol at 150 °C for 2.5 h being 60.2% and 68.3%, respectively. The reusability-experiment results indicate that Ni–CeO2/CN maintained a high catalytic activity in five reaction runs, making this a promising route for C–O ether bond cleavage under mild conditions.
研究领域:
催化化学
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生物质转化
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材料科学
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
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2015
·Vol. 17
·期 5
·3010-3017
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IF 8.02
Yao-Bing Huang,Long Yan,Meng-Yuan Chen,Qing-Xiang Guo,Yao Fu
Direct hydrogenolysis of the aromatic Csp2–O bonds in both phenols and phenyl ethers to form arenes selectively is a core enabling technology that can expand greatly the scope of chemical manufacture from biomass. However, conventional hydrogenolysis of phenols typically led to aromatic ring saturation instead of the cleavage of the Csp2–O bonds. Herein, we report a recyclable Ru–WOx bifunctional catalyst that showed high catalytic activities for the hydrogenolysis of a wide range of phenols and phenyl ethers, including dimeric lignin model compounds and the primitive phenols separated from pyrolysis lignin, to form arenes selectively in water. Preliminary mechanistic studies supported that the reactions occurred via a direct cleavage of the Csp2–O bonds and the concerted effects of the hydrogenating Ru sites and the Lewis acidic W sites are the key to such an unusual reactivity.
研究领域:
催化化学
·
可再生资源化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2017
·
IF 3.204
Chen Zhu,Jing-Pei Cao,Xiao-Yan Zhao,Tao Xie,Jie Ren,Xian-Yong Wei
Selective cleavage of C O bonds in benzyl phenyl ether (BPE) as a typical lignin α-O-4 ether to produce aromatics is a challenging and attractive topic. Herein, the earth-abundant first-row transition metals, such as Co, Ni and Cu were supported on activated carbon (Co/AC, Ni/AC and Cu/AC) to identify their ability for cleaving C O bond of BPE. Among these catalysts, Ni/AC exhibit highest activity for cleavage of C O bond. The reaction with BPE was carried out at pretty mild condition of 140 °C and 2 MPa H 2 , which is highly selective afforded toluene and phenol as the major products with the optimum yields of 88.5 and 86.5%, respectively. Based on the test, the reaction pathways were proposed. A abundant of dissociated H· atoms on Ni(0) sites forms surface active Ni H species; Ni(0) activates and facilitates cleavage of the C O bond in BPE to form benzyl (C 6 H 5 C·) and phenoxy radicals (C 6 H 5 O·); H· atoms spill from active species Ni H recombined together with C 6 H 5 C· and C 6 H 5 O· forming the products of toluene and phenol, respectively.
研究领域:
化学
·
催化科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Lin Hu,Jingcheng Wu,Xian-Yong Wei,Changlin Yu,Lei Li,Lingling Li
Exploring the value-added utilization of lignin showed the great significant to realize the efficient conversion of lignocellulosic biomass, which had good environmental, economic, and social benefits. However, the catalytic hydrogenolysis of lignin faced the great problems, including harsh reaction conditions and low product yield. In this research, the FeOx modified Ru/mordenite (M) was synthesized by deposition–precipitation method and strengthened the effective lignin conversion process. Ru 2.5% Fe 2.5% /M showed the high catalytic hydrogenolysis activity of β-O-4 and α-O-4 bond under the condition of 260 °C, 1 MPa H 2 , and 3 h in the methanol. Though the research about reaction of model compounds and several characterizations, synergistic action of highly dispersion RuFe nanoparticles and acidic sites significantly promoted the breakage of C-O bond. The introduction of Fe species can reduced the size of metal nanoparticles. The lignin oil reached the high value of 47.8 wt%, and contained the low RC value of phenolic compounds. Finally, the reaction mechanism of lignin catalytic hydrogenolysis was discussed, and it found that the highly dispersed RuFe nanoparticles enhanced the synergistic transfer ability of H 2 and methanol to release H•. This research would give some useful understandings for the efficient thermochemical conversion of lignin.
研究领域:
催化化学
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生物质能
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Joule
·
2019
·
IF 0
Man Yang,Haifeng Qi,Fei Liu,Yujing Ren,Xiaoli Pan,Leilei Zhang,Xiaoyan Liu,Hua Wang,Jifeng Pang,Mingyuan Zheng,Aiqin Wang,Tao Zhang
Cellulosic ethanol is one of the most important biofuels, yet its commercial production is hindered by the low-efficiency and high-cost bioconversion process. Here, we report a new chemocatalytic approach for the one-pot production of cellulosic ethanol. With a multifunctional Mo/Pt/WO x catalyst, cellulose is directly converted to ethanol in a one-pot reaction with a yield as high as 43.2 C%. Kinetic analysis reveals that such a one-pot process involves tandem catalysis from cellulose to ethylene glycol (rapid) followed by hydrogenolysis of ethylene glycol to ethanol (slow). Characterizations show that isolated and low-coordinated MoO x bonds to metallic Pt particles on the mesoporous WO x support, constituting x OMo–Pt–WO x interfacial sites, which offer high activity for C–O cleavage of ethylene glycol.
研究领域:
化学工程
·
可再生资源与环境科学
✓ 已验证
DOI
ChemCatChem
·
2016
·Vol. 8
·期 11
·1929-1936
·
IF 4.724
Bin Chen,Bin Zhang,Yibo Zhang,Xiangguang Yang
Graphical Save it for a Raney day : A series of Ag-modified Ni catalysts is prepared, and the role of bimetallic effects on the selective cleavage of C−O and C−C bonds is investigated in glycerol hydrogenolysis, a model reaction for the utilization of biomass-derived polyols. Compared to Raney Ni, the optimal Raney Ni 6 Ag catalyst is more active in glycerol conversion and efficient for C−O bond cleavage to afford a higher selectivity toward C 3 products. A series of Ag-modified Ni catalysts was prepared, and the role of bimetallic effects on the selective cleavage of C−O and C−C bonds was investigated in glycerol hydrogenolysis, a model reaction for the utilization of biomass-derived polyols. Compared to Raney Ni, the optimal Raney Ni 6 Ag catalyst was more active in glycerol conversion and efficient for C−O bond cleavage to afford a higher selectivity toward C 3 products (1,2-propanediol and lactic acid; 88 %) at the same ∼70 % conversion of glycerol, especially 1,2-propanediol (73 %). On Ni catalysts, the hydrogenation of adsorbed species was the most likely rate-limiting step in glycerol hydrogenolysis under alkaline conditions. The Ag additive enhanced the hydrogenation ability of Ni catalysts, which should be related to the higher strength of the adsorption of hydrogen and the lower strength of the adsorption of substrates on Ni sites because of the formation of Ni-Ag alloys. A mechanistic interpretation was presented for the excellent catalytic behavior.
研究领域:
催化化学
·
生物质利用
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）