JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2023
·
IF 6
Dayi Guo,Bo Cai,Rui Kang,Shuai Wang,Junfeng Feng,Hui Pan
Hydrodeoxygenation is one of the key steps to upgrade of biomass derived bio-oil into valuable biofuels and chemicals. Developing of highly reactive and cost-effective catalysts for bio-oil hydrodeoxygenation is highly desired. Layered Ni x Co y Al z catalyst was prepared using layered double hydroxide (LDH) as the precursors. The optimized Ni 1 Co 3 Al 2 -600 catalyst exhibits excellent catalytic performance for guaiacol hydrodeoxygenation. Guaiacol could completely converted with 90.0% of cyclohexanol selectivity under relatively mild reaction conditions. The XRD and HRTEM characterizations of the as prepared catalysts confirmed the formation of Ni-Co alloy and the XPS analysis revealed the strong interaction between Al species with both Ni and Co in catalyst Ni 1 Co 3 Al 2 -600, which should contribute to its high catalytic activity for guaiacol hydrodeoxygenation. Catalyst Ni 1 Co 3 Al 2 -600 also demonstrated excellent versatility for the hydrodeoxygenation reactions of guaiacyl and syringyl compounds as well as high stability. The results from this work could provide a new approach for the constructing of effective catalysts from non-noble metal LDHs.
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
ACS Catalysis
·
2016
·
IF 9.307
Jingbo Mao,Jinxia Zhou,Zhi Xia,Zhiguang Wang,Zhanwei Xu,Wenjuan Xu,Peifang Yan,Kairui Liu,Xinwen Guo,Z. Conrad Zhang
Gold nanoparticles on a number of supporting materials, including anatase TiO2 (TiO2-A, in 40 nm and 45 μm), rutile TiO2 (TiO2-R), ZrO2, Al2O3, SiO2 , and activated carbon, were evaluated for hydrodeoxygenation of guaiacol in 6.5 MPa initial H2 pressure at 300 °C. The presence of gold nanoparticles on the supports did not show distinguishable performance compared to that of the supports alone in the conversion level and in the product distribution, except for that on a TiO2-A-40 nm. The lack of marked catalytic activity on supports other than TiO2-A-40 nm suggests that Au nanoparticles are not catalytically active on these supports. Most strikingly, the gold nanoparticles on the least-active TiO2-A-40 nm support stood out as the best catalyst exhibiting high activity with excellent stability and remarkable selectivity to phenolics from guaiacol hydrodeoxygenation. The conversion of guaiacol (∼43.1%) over gold on the TiO2-A-40 nm was about 33 times that (1.3%) over the TiO2-A-40 nm alone. The selectivity of phenolics was 87.1%. The products are mainly phenolic compounds with no aromatics and saturated hydrocarbons such as cyclohexane. The gold particle size ranging from 2.7 to 41 nm and water content were found to significantly affect the Au/TiO2-A-40 nm catalyst activity but not the product selectivity. The reaction rates of 0.26 and 0.91 (min–1 g-cat–1 cm3) were determined for guaiacol hydrogenation and catechol hydrogenation, respectively. Bimolecular methylation was established as the dominant mechanism for methyl group transfer among the phenolics. Two major pathways of guaiacol hydrogenation to phenolics over the 0.4Au-19 nm/TiO2-A-40 nm are proposed: (1) direct hydrogenation of guaiacol to form phenol and methanol, (2) hydrodehydroxylation of catechol intermediate from the transmethylation between guaiacol and phenol.
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
JOURNAL OF CATALYSIS
·
2018
·
IF 6.759
Kairui Liu,Peifang Yan,Hong Jiang,Zhi Xia,Zhanwei Xu,Shi Bai,Z. Conrad Zhang
Selective hydrocleavage of aromatic C O bond while preserving the aromatic ring is a desired catalytic process in hydrodeoxygenation (HDO) of biomass derived aromatic oxygenates to high value biochemicals. Guaiacol with typical methoxy and phenolic hydroxyl groups is a representative aromatic di-oxygenates of lignin fragments. Sub-nanometer sized silver, a poor hydrogenation metal catalyst, was found to initiate H 2 dissociation and H spillover onto anatase TiO 2 (TiO 2 -A) surface. The spillover hydrogen enhanced the partial reduction of TiO 2 -A surface at a substantially lowered temperature as compared to the reduction of TiO 2 -A by molecular H 2 . The reduction of TiO 2 -A surface by spillover hydrogen was enhanced at Ag loading as low as 0.01 wt% on TiO 2 -A. The ratio of spillover H to Ag was as high as 675 at Ag loading of 0.01 wt% and the ratio decreased with increasing Ag loading. We found that the yield of phenolic products was linearly correlated with the amount of spillover hydrogen that created oxygen vacancy (Ov) through partial reduction of TiO 2 -A surface. Methanol was formed as the main side-product, indicating that the direct hydrocleavage of aromatic C-OCH 3 in guaiacol is favored over that of aromatic C-OH on the created site.
研究领域:
催化化学
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生物质能
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
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2022
·Vol. 12
·期 4
·371
·
IF 4.501
Minghao Zhou,Fei Ge,Jing Li,Haihong Xia,Junli Liu,Jianchun Jiang,Changzhou Chen,Jun Zhao,Xiaohui Yang
Lignin is an attractive renewable source of aromatics with a low effective hydrogen to carbon ratio (H/Ceff). The catalytic hydrodeoxygenation (HDO) of lignin-derived model compounds is a key strategy for lignin upgrading. In this work, the HDO of guaiacol, a typical lignin-derived compound, was carried out over metal–organic framework (MOF)-derived Ni-based catalysts. A monometallic Ni-MOF catalyst and different ratios of bimetallic NiMo-MOF catalysts were synthesized by a hydrothermal process, followed by a carbonization process. Among these catalysts, Ni3Mo1@C exhibited an excellent catalytic performance, affording a guaiacol conversion of 98.8% and a cyclohexanol selectivity of 66.8% at 240 °C and 2 MPa H2for 4 h. The addition of Mo decreased the particle size of the spherical structure and improved the dispersion of metal particles. The synergistic effect between Ni and Mo was confirmed by various means, including ICP, XRD, SEM, TEM, and NH3-TPD analyses. In addition, the effect of the reaction temperature, time, and H2pressure during the HDO process is discussed in detail.Keywords:guaiacol;hydrodeoxygenation;Ni-based bimetallic catalysts;MOF
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
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
·
IF 8.1
Xiaoqing Huang,Haoyu Su,Ping Hu,Yueyuan Ye,Duo Wang
To fully utilized the high value-added phenolic compounds in biomass pyrolysis bio-oils, a heterogeneous extraction method was developed in this study to separate 4-ethylguaiacol, guaiacol, and eugenol from bio-oil one by one. Based on the high selectivity of coordination intermediates generated between Ca 2+ and phenolic compounds with hydroxyl and methoxy groups towards the parent phenol, the reaction intermediate between each of 4-ethylguaiacol, guaiacol, eugenol and Ca 2+ was used as the extracting agents. Influencing parameters investigated were the sequence of extracting three phenolic compounds from the model bio-oil, the optimal extraction conditions, and the Ca 2+ distribution in the original extracting agents at the end of the reaction. The optimal extraction sequence was determined to be 4-ethylguaiacol, eugenol and guaiacol through the evaluation of multiple experiments changing their addition sequence. Under the conditions of 25 °C reaction temperature, 45 min reaction time, and pH value of 7, the extraction efficiency of 4-ethylguaiacol, eugenol and guaiacol from bio-oil reached 60.6 %, 46.1 % and 60.7 %, respectively. Meanwhile, the purity of these three phenolic compounds achieved 62.4 %, 90.0 % and 89.0 %.
研究领域:
化学工程
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生物质能
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Mingqiang Chen,Wei Dai,Yishuang Wang,Zhiyuan Tang,Hong Li,Chang Li,Zhonglian Yang,Jun Wang
Lignin catalytic depolymerization (LCD) into liquid fuels and aromatic chemicals in supercritical ethanol systems is one of the most effective strategies for efficient utilization of biomass resources. In this study, a series of sepiolite (SEP) supported Mo-Mn catalysts with different Mn/Mo ratios were prepared and applied to LCD. Experimental results for lignin and 2-phenoxy-1-phenyl ethanol (PP) confirmed that Mo/Mn species promoted the breakage of β-O-4 bonds, Mn additive effectively inhibited the alkylation of intermediates, and Mn/Mo ratios distinctly affected the yields of lignin oil (LO) and guaiacols. All as-prepared Mn-Mo/SEP catalysts achieved approximately 100 % conversions of lignin and PP. Various characterization results demonstrated that Mn/Mo ratios could regulate the particle sizes of metal oxides as well as the concentration of oxygen vacancies (O V ) and surface acidic sites. In 3Mn1Mo/SEP, the appropriate interaction among SEP , Mn and Mo species reduced the particle sizes of metal oxides and rendered the crystalline phase structure in a relatively complex state, which undoubtedly generated massive steps/corners on its surface and then enhanced the hydrogenation reaction. Furthermore, the 3Mn1Mo/SEP contained many O V and suitable distribution of Lewis and Brønsted acid sites, which facilitated the adsorption of oxygen-containing intermediates and further hydrogenation and deoxygenation. Therefore, 3Mn1Mo/SEP achieved 45.7 % of LO yield with an HHV of 32.31 MJ/Kg and the highest selectivity to phenols (85.61 %) and yield of guaiacols (308.9 mg/g lignin). In addition, the plausible reaction network for LCD was proposed based on the results of experiments and characterizations.
研究领域:
生物质能
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2022
·
IF 9.136
Weiyan Luo,Yixin Chen,Ping Hu,Wei Ruan,Yueyuan Ye,Zhifeng Zheng,Shuirong Li,Dechao Wang,Duo Wang
A heterogeneous extracting route of 4-ethylguaiacol is constructed using the intermediate of the reaction between 4-ethylguaiacol and Ca 2+ as the extracting agent. In this work, 4-ethylguaiacol with different concentrations (70, 80, 90, 95%) is prepared using 40 v/v% ethanol aqueous solution as the mother liquor. The extraction parameters optimization, cycle extraction and 4-ethylguaiacol purification are studied, respectively. Extracting parameters investigated are reaction temperature (4–80 ℃), extraction time (5–60 min), and pH value (6.5–13). 4-ethylguaiacol extraction efficiency keeps above 90% at the optimum extracting conditions at the reaction temperature of 4–20 ℃, the extraction time of 30 min, and the pH value of 6.5–10. Further cycle extraction experiments are carried out under the optimal extraction parameters using the intermediate as the extracting agent. After 36 cycle extraction times, the extraction efficiency of 4-ethylguaiacol can still reach 91.7%. Guaiacol has similar physical and chemical properties to 4-ethylguaiacol, thus it is used as an impurity to test the extraction and purification effect of the heterogeneous extracting method. With increasing the cycle extraction times from 1 to 4, 4-ethylguaiacol purity reaches more than 99% for all four mother liquors with different initial concentrations. 4-ethylguaiacol purity of 99.57% is achieved through twice cycle extraction when its initial content in the mother liquor is 95%.
研究领域:
化学工程
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生物化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2024
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IF 7.1
Leipeng Liu,Haochen Yun,Xiaofei Chen,Yuanduo Duan,Zhe Ji,Shenghua Lv,Yuehong Zhang
Film capacitors make extensive use of polymer dielectrics. However, most of the currently studied dielectric film substrate feedstocks are from fossil energy sources. Herein, a series of biobased dielectric copolymers poly(guaiacol methacrylate-methyl methacrylate) [P(GEMA-MMA)] originating from the biobased origin guaiacol have been reported. P(GEMA-MMA) was produced by copolymerizing GEMA and MMA. Anew type of dielectric film with excellent comprehensive performance was obtained. The guaiacol structure in the copolymer has higher HOMO levels that could take charge traps and capture free charge carriers in the polymer, thus endowing the polymer with excellent energy storage performance. P(GEMA-MMA)-1:7 possess a high breakdown strength Eb of 710.5 MV/m at room temperature, which was 32.5% higher than that of pure PMMA. The charge–discharge efficiency was 87.0% at 500 MV/m, which was much higher than that of pure PMMA (70% under 500 MV/m). Even at 100 °C, the energy storage efficiency of P(GEMA-MMA)-1:7 still can be maintained at a high level of 84.7%. This work offers a practical method for producing biobased dielectric films with outstanding all-round performance.
研究领域:
材料科学
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能源存储
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2018
·
IF 4.521
Junbo Feng,Wei Jiang,Caicai Yuan,Xiancai Shi,Kai Zang,Yadong Zhang
A novel core/shell nano-bimetallic catalyst SiO 2 @Ni-Rh was successfully prepared by deposition–precipitation method, using liquid ammonia as a precipitating agent. SEM, TEM, XRD, XPS, H 2 -TPR, H 2 -TPD and adsorption/desorption of nitrogen were employed to systematically investigate the surface morphology, size, chemical composition, reducibility, Ni dispersion and structure of the as-synthesized nanoparticles. It is found that the nickel and rhodium are uniformly dispersed on the silica surface to form core/shell SiO 2 @Ni-Rh nanoparticles with Ni atoms and Rh atoms as the outer shell and SiO 2 as the core, which possess high dispersion of Ni on the surface and high specific surface area (234.063 m 2 /g) of the catalyst with the mean particle size of ca. 130 nm. The dehydrogenation of 2-methoxycyclohexanol to guaiacol was used as the model reaction for evaluating the catalytic activity of the as-synthesized core/shell various Ni and Rh-containing bimetallic nanoparticles in a tubular stainless steel reactor. SiO 2 @15Ni-0.4Rh nanoparticles have exhibited remarkable catalytic performance, with 98.3% conversion and 93.6% selectivity of guaiacol, due to high dispersion of metal nanoparticles and synergistic effect of bimetallic Ni-Rh over the special core/shell SiO 2 @Ni-Rh by the addition of rhodium. Furthermore, turn over frequency value of SiO 2 @15Ni-0.4Rh nanoparticles achieves 0.47 s −1 , showing high catalytic efficiency. In general, the dehydrogenation of 2-methoxycyclohexanol over the core-shell-like SiO 2 @Ni-Rh nanoparticles in a continuous fixed-bed reactor is a more promising, high atom economy, high efficient, easy separation, environmental friendliness, green synthetic pathway of guaiacol.
研究领域:
催化化学
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材料科学
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绿色化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2024
·Vol. 14
·期 12
·3382-3395
·
IF 4.4
Xiaohan Qu,Saibei Zhang,Jingbo Mao,Hui Lv,Jinxia Zhou
Heretofore selective hydrodeoxygenation (HDO) of syringol remained limited and challenging due to the complicated structure of syringol compared to other lignin-derived model compounds such as guaiacol and phenol. Here, we report an efficient HDO of syringol to cyclohexanol (CYHAOL) over a reduced graphene oxide (rGO)-supported Co catalyst (Co/rGO) capable of heterolytic dissociation of H2 molecules. A combination of characterization methods, including HAADF-STEM, XPS, XRD, etc., and experiments reveals that Co/rGO has a unique morphology composed of core–shell structured multivalent Co oxide nanoparticles (CoOx) incorporating oxygen vacancies distributed on the graphene surface, and high-density single Co atoms embedded in the graphene matrix, both of which can afford the highly active Hδ− species for the HDO reaction. The morphologies of the supported Co species are highly dependent on the graphene textures. The Co/rGO catalyst without pre-reduction treatment demonstrated exceptional catalytic activity in the HDO of syringol with high selectivity to CYHAOL under mild conditions and good stability in the catalyst components. The metal-oxide-based Co/rGO catalyst does not require the pre-reduction treatment, simplifying the catalyst preparation process and eliminating the severe sintering of the metal species.
研究领域:
催化化学
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材料科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
Phytochemistry Letters
·
2024
·
IF 1.3
Xi-Long Guo,Chun-Yan Zhao,Cui-Ping Zhang,Yi Zhu,Qing-Rong Wu,Yuan-Qing Zhou,Ya-Hong Fei,Fang Ge,Wei Shi
In this letter, we reported synthesis of 2,4-Diacetylphloroglucinol (DAPG) derivatives as a new class of anti fungal agents . A series of DAPG ester analogues with diverse length of acyl substitution on aromatic hydroxyls were synthesized and characterized by 1 H, 13 C NMR and ESI-MS. Their antifungal activities were evaluated in vitro against six important plant fungal pathogens using mycelial growth inhibitory rate assay. A clear structure-activity relationship (SAR) study of the diacylphloroglucinols was investigated. Compounds 2 , 2a - d , 2i , 2j and 2k exhibited broad-spectrum anti fungal activity, in addition, the anti fungal activity was correlated with the lipid-water partition coefficient of the compounds (log P ), these active analogues have log P between − 0.53 and 0.19. Particularly compound 2k (log P 0.19) was found active to Glomerella cingulata with IC 50 value of 1.26 μ g/mL; compound 2 (log P − 0.51) was identified the most active one against Pyricularia oryzaecar (IC 50 1.52 μ g/mL). The results suggest that compound 2 and 2k might be promising candidates in the development of new pesticides.
研究领域:
植物化学
·
农药学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2016
·
IF 3.926
Xiao-Fei Gu,Yue Zhao,Kan Li,Meng-Xiang Su,Fang Yan,Bo Li,Ying-Xiang Du,Bin Di
Structure elucidation of volatile aromatic isomers at trace level has long been considered as an elusive task, due to their structural similarities and similar polarities, even with the aid of many spectroscopic techniques such as mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy. Single-crystal X-ray diffraction (SCD) is recognized as one of the most powerful structural elucidation techniques. The recently developed crystalline sponge method overcomes the intrinsic limitation of SCD that the target molecules must be single crystals, being able to analyze non-crystalline and trace-amount compounds without any special treatment. In order to investigate whether the crystalline sponge method could be used for the structure elucidation of closely related isomers or other volatile and even oily compounds in complex mixtures at trace level, we combined HPLC separation with the crystalline sponge method for X-ray crystallographic analysis. In this paper, two pairs of volatile aromatic isomers including cis / trans isomers of asarone and positional isomers of carvacrol and thymol, as well as the main volatile component in essential oil extracted from Acorus Tatarinowii , were first isolated by HPLC and encapsulated into the crystalline sponge then elucidated by X-ray crystallographic analysis. Direct observation of these volatile compounds by X-ray crystallography was achieved using only microgram quantities without crystallization or derivatization. Unambiguous identification of these compounds was realized without reference standards. This strategy offers a promising platform capable of providing high-confidence detailed structural information of closely related isomers as well as other volatile and even oily compounds in complex mixtures in microgram quantities.
研究领域:
分析化学
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晶体学
·
药学
✓ 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）