Catalysts
·
2019
·Vol. 9
·期 11
·899
·
IF 3.444
Wei Xu,Lijing Gao,Guomin Xiao
Nano-sized HZSM-5 (n-HZSM-5) was synthesized and applied in the aromatization of glycerol. The effects of additives (carboxymethylcellulose sodium, NaCl, sodium alginate, etc.) on the chemical and physic properties of n-HZSM-5 during preparation were investigated. Metal modification was also investigated based on the synthesized n-HZSM-5. The results showed that the addition of carboxymethylcellulose sodium (CMC-Na), NaCl and sodium alginate (SA) led to forming smaller sizes of HZSM-5 and promoted the acid amounts of the catalysts, which increased its catalytic activities for obtaining BTX. The highest BTX yield of ~35% was obtained by SA derived n-HZSM-5, and the life of the catalyst were both obviously promoted by the additives with a highest of ~11 h by γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH-560) derived n-HZSM-5. BTX yields could be improved by 40%by the addition of Zn and Cd in n-HZSM-5 while having little effect on the catalyst life.
研究领域:
催化化学
·
纳米材料科学
·
绿色化学
✓ 已验证
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2021
·Vol. 13
·期 12
·10701-10710
·
IF 4.987
Zeng Qin,Du Zhenyu,Luo Ligang
In this study, different bimetallic (Ru, Pd, and Pt) catalysts over a variety of supports (activity carbon, γ-Al 2 O 3 , TiO 2 , HZSM-5) were employed to improve the kraft lignin depolymerization process using isopropanol as in situ hydrogen source. The effect of catalysts was firstly investigated, which suggested that 1wt%Ru-1wt% Pd/HZSM-5 promoted the hydrogenolysis and hydrodeoxygenation effect on conversion of kraft lignin (95.86 wt%) and the selectivity of aliphatic alcohol (26.92 wt%) and hydrocarbon monomers (35.73 wt%), respectively. The effect of temperature and reaction time were also discussed, which indicated that the high temperature (250 to 310 °C) promoted the hydrogenolysis process; while the temperature is higher than 310 °C, the repolymerization process was appeared, leading to the decreasing yield of total monomers. For the influence of reaction time, it was noted that the optimal reaction time to acquired high yield and selectivity of aliphatic alcohol and hydrocarbon monomer was 120 min. It was also conducted FTIR and 2D HSQC NMR analysis to understand the effective depolymerization of the major linkages with attacked by the Ru-Pd/HZSM-5 catalyst, which was corresponding with the results with GC–MS. Graphical abstract
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
FUEL PROCESSING TECHNOLOGY
·
2020
·
IF 4.982
Zi Zeng,Jiaoyang Xie,Yue Guo,Ruiheng Rao,Bo Chen,Lihua Cheng,Ying Xie,Xinping Ouyang
Highly dispersed Fe Pd bimetallic catalyst supported on HZSM-5 (Fe-Pd/HZSM-5) was prepared by impregnation method for the hydrogenolysis of lignin. The correlation between the textural properties of the catalyst and its catalytic activity to lignin hydrogenolysis were investigated. The presence of Fe facilitates the dispersion of Pd, and the particle size decreases from 6.1 nm for 3.0 wt% Pd/HZSM-5 (Pd-3.0) to 2.5 nm for 9.0 wt% Fe-1.0 wt% Pd/HZSM-5 (FP-1.0). Fe is mainly existed in the oxidized state which means that electrons in Pd tend to transfer to FeO x , facilitating the activation of H 2 to form active H atoms. Due to the geometric and electronic synergistic effects , FP-1.0 bimetallic catalyst exhibits a good catalytic activity to lignin hydrogenolysis, contributing to as higher as 98.17% of lignin conversion and 27.92% of aromatic monomers yield under the optimal reaction conditions of 1 MPa H 2 at 320 o C for 120 min in ethanol-water solvent. FP-1.0 bimetallic catalyst with low cost and highly catalytic activity may be a potentially useful catalyst for selective hydrogenolysis of lignin.
研究领域:
催化化学
·
生物质能
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2023
·
IF 5.7
Yongjin Hu,Zhichang Jiang,Runxian Wang,Shujie Gao,Hui Liu,Haining Wang,Dong Ye
In this article, the effects of K species, including K 2 O, KCl, and K 2 SO 4 , on the Hg 0 removal capability of MnO x /HZSM-5 adsorbent were investigated. Adding K 2 O and K 2 SO 4 interfered with the Hg 0 removal process; as the loading amount of these two K species increased, this adverse impact became more obvious. This was because the added K 2 O or K 2 SO 4 lowered the acidity and oxidizability of the adsorbents via the interactions with MnO x , which exerted an inhibitory effect on the adsorption and oxidation of Hg 0 . By contrast, introducing KCl made almost no adverse impacts on the Hg 0 elimination ability of the adsorbents. With rising the KCl content to 4 wt%, even ∼92.7% Hg 0 removal efficiency was obtained. This could be attributed to the presence of Cl − ; with the guidance of high-valence-state metal cations and O 2 , Cl − could be converted to active chlorine species, which was capable of transforming Hg 0 to HgCl 2 . This finding supplied a theoretical basis for developing new adsorbents that were capable of stably operating in the power plants with high-alkali-content coal utilized.
研究领域:
环境科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2018
·
IF 4.667
Chuanhui Zhang,He Huang,Genqin Li,Lei Wang,Liang Song,Xuebing Li
Series of 10% MnO x /HZSM-5 catalysts with different zeolitic Si/Al ratios were prepared by an incipient impregnation method and evaluated for the catalytic oxidation of toluene. Characterization results indicated that all catalysts exhibited similar textural and redox properties but variable surface acidity. Catalytic testing results showed that the catalytic activities over these catalysts followed a descending order of 10% MnO x /HZSM-5-25 > 10% MnO x /HZSM-5-50 > 10% MnO x /HZSM-5-75, where 10% MnO x /HZSM-5-25 exhibited the optimum catalytic activity and excellent catalytic durability under dry condition and good water-resistant ability under humid condition. A good linear relationship between the toluene conversion efficiency (TOF Mn ) and the total acidity over MnO x /HZSM-5 catalysts was obtained, which revealed the crucial role and promotional effect of zeolitic acidity acting as a promoter on the catalytic activity for toluene oxidation.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2021
·
IF 5.541
Yi Wei,Xiying Jia,Chaoyue Shen,Huijuan Ying,Fengwen Yu,Jianbing Ji
Digestate (DE), the residue following anaerobic digestion , has been well utilized as a potential feedstock of molten carbonates pyrolysis and catalytic reforming . The lignin of DE was converted into phenolics, guaiacols and furfural with molten carbonates pyrolysis, and further upgraded to bio-based monophenols by coupling with modified HZSM-5 catalyst. The maximum monophenols yield could achieve 7.22 g/100 g of digestate, and 81.34% of the organic phase of bio-oil at the optimum reaction conditions. The alkali-treated and Fe-loaded on HZSM-5 catalyst, with enhanced pore diameter distinctly and mild acidity, has an outstanding selectivity for monophenols and preferable anti-coking ability in integrated pyrolysis system, while with quite a low catalyst coke yield of 3.97%. The results indicated that the formation of mesopores might minimize the diffusion hindrance of the reactant molecules and reduce coke accumulation. In addition, according to the experiment conducted on a self-designed thermogravimetric analysis device, the kinetic study of the digestate with molten carbonates certificated that the reaction rate of pyrolysis had been promoted by both decreasing activation energy and intensification of heat transfer.
研究领域:
生物化学工程
·
可再生能源技术
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2024
·
IF 5.8
Shan Cheng,Yi Fu,Hong Tian,Yi Cheng,Jiawei Wang,Jiang Zhu,Linxi Guo,Xuan Huang
The selectivity and catalytic mechanism of HZSM-5 in the pyrolysis of lignin model compounds at 600 °C were investigated using Py-GC/MS and density functional theory (DFT). The findings indicate that HZSM-5 elevated the relative content of aromatic hydrocarbons in the pyrolysis products of phenol, vanillin, and syringol by 12.3 %, 11.7 %, and 7.5 %, respectively. Meanwhile, the relative content of oxygen-containing products, including aldehydes and acids, was reduced by 15.7–52.0 %. Throughout the pyrolysis of lignin model compounds, various side chain reactions take place, such as dissociation, decarbonylation, isomerization rearrangement, alkylation, and aromatization. The selective catalytic decomposition mechanism of HZSM-5 on oxygen-containing functional groups involves both the physical selection imparted by the pore size structure and the selection of acid sites that form hydrogen bonds with hydroxyl, carbonyl, and methoxy groups. This mechanism was corroborated by DFT calculations, which showed that the energy barriers for the removal of most oxygen-containing functional groups were lowered by 1.7–72.4 kJ/mol. These results provide an in-depth understanding of the catalytic pyrolysis of lignin and pave the way for future research on the high-value utilization of waste lignin.
研究领域:
生物质能
·
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Jing Zhang,Xun Kuang,Linyu Zhu,Xintong Xiao,Zhongyue Zhou,Fei Qi
Despite the crucial roles of cyclohexanones across various industrial sectors, notably in the production of nylon and plastics, their conventional production heavily relies on fossil resources. The exploration of highly efficient routes to convert renewable biomass into cyclohexanones holds promise for advancing sustainable chemical processes, especially with the growing concerns in energy and the environment. Herein, we report the direct conversion of lignin-derived phenolic compounds to cyclohexanones through hydrodeoxygenation using PdFe/HZSM-5 catalysts. The successful achieved conversion of guaiacol was up to 97.27%, with a greatest selectivity of 90.59% to cyclohexanone on PdFe1.5/HZSM-5. Characterization of the catalysts further revealed that bimetallic catalyst promoted the dispersion of PdFe on HZSM-5 and facilitated the interactions between PdFe because of electron transfer, which collectively facilitated surprising outcomes. This work offers a promising strategy for improving lignin valorization within the context of producing sustainable chemicals and industrial materials.
研究领域:
化学工程
·
可再生资源与环境科学
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2017
·Vol. 10
·期 6
·1376-1384
·
IF 4.803
Zhaoxia Zheng,Zhicheng Luo,Chen Zhao
Graphical Taking the cross : Morphologically cross-shaped HZSM-5 loaded Ru nanoparticles demonstrate high activity (rate: 7.8 g g −1 h −1 ) in the selective hydrogenolysis of guaiacol to benzene in water with a nearly quantitative yield accompanied with high durability. Hydrogenolysis of C−O bonds is an important tool for synthesis of valuable fuels and chemicals from biomass. In this contribution, we report that morphologically cross-shaped HZSM-5-loaded Ru nanoparticles have demonstrated high activity in the selective hydrogenolysis of guaiacol to benzene in water with 97 % yield and a rate of 7.8 g g −1 h −1 accompanied with high durability. N 2 sorption analysis showed that Ru/HZSM-5 (cross-shaped) had a large mesoporous surface area and pore volume for loading small and uniform Ru nanoparticles, as confirmed by TEM images. The stronger interaction of Ru and cross-shaped HZSM-5 was simultaneously confirmed by a higher hydrogen reduction temperature of RuO 2 on calcined Ru/HZSM-5, a blueshift of Ru δ+ -(CO) n , Ru δ+ -(CO), and Ru 0 -(CO) species in the IR spectra of adsorbed CO, and a higher Ru 3d 5/2 binding energy in X-ray photoelectron spectroscopy measurements. The reaction constant in guaiacol hydrogenolysis to phenol over cross-shaped Ru/HZSM-5 (0.051 min −1 ) was 3–4 times higher than that on spherical and cuboid Ru/HZSM-5 (0.012–0.029 min −1 ) at identical conditions, attributed to the remarkable hydrogenolysis catalytic capability of Ru nanoparticles on cross-shaped HZSM-5. In addition, adsorption of guaiacol and hydrogen was more substantial on cross-shaped Ru/HZSM-5, as evidenced by of IR and mass spectroscopy, respectively. The higher adsorption of guaiacol is attributed to the abundant Lewis acid sites on cross-shaped Ru/HZSM-5, as the Al−OH enriched Lewis acid sites favor the adsorption of oxygen-containing guaiacol. The higher rate constant in the primary step, together with the adsorbed high concentrated reactant and hydrogen (with nearly first-order reaction kinetics) on cross-shaped Ru/HZSM-5, facilitates the overall tandem reaction, leading to an excellent hydrogenolysis catalyst working at hydrothermal conditions for biomass conversion.
研究领域:
催化化学
·
能源化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2020
·Vol. 34
·期 11
·e5932
·
IF 3.14
Yanming Jia,Junwen Wang,Kan Zhang,Chuanmin Ding
A highly shape-selective and relatively long-lifetime HZSM-5-based catalyst (Zn-2P/HZSM-5) was prepared by chemical modification with both ZnSiF 6 ·6H 2 O and H 3 PO 4 solution. The phosphoric acid modification could effectively modulate the Brønsted acid strength of the HZSM-5 catalyst, which promotes the oligomerization, alkylation, cyclization, and hydrogen transfer reactions. The introduction of Zn-Lewis acid sites significantly improved the dehydroaromatization of higher olefins. All of these were very beneficial for the generation of BTX (i.e. b enzene, t oluene, and x ylene) hydrocarbons in aromatization of methanol. The coke amount and the average rate of coke formation decreased over the Zn-2P/HZSM-5 catalysts, which may largely be ascribed to its lower strong acid sites and lower outer surface acidity. The catalytic performance of methanol aromatization showed that the Zn-2P/HZSM-5 catalyst exhibited the highest BTX selectivity of about 46.76% and the longest catalytic lifetime of about 498 h at T = 400 °C, P = 0.1 MPa, and weight hourly space velocity = 0.7 h −1 .
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2019
·
IF 3.774
Yun-Peng Zhao,Fa-Peng Wu,Qing-Lu Song,Xing Fan,Li-Jun Jin,Rui-Yu Wang,Jing-Pei Cao,Xian-Yong Wei
In this work, a bimetallic catalyst of Pd and Ni supported on HZSM-5 was designed and evaluated in the hydrodeoxygenation of model compounds representing various C–O bonds in lignin. The effects of temperature, holding time, and initial H 2 pressure on the catalytic performance of the Pd–Ni/HZSM-5 catalyst were investigated. The results indicated that the Pd–Ni/HZSM-5 catalyst exhibited superior catalytic activity towards the conversion of the model compounds to alkanes compared to its monometallic counterparts. Direct cleavage of the C–O bond in DPE was achieved under low H 2 pressure, mainly producing benzene and minor amounts of phenol and cyclohexane, while at high H 2 pressure, the reaction pathway was altered towards hydrogenation of the benzene ring , followed by then cleavage of the C–O bond to afford only cyclohexane. Moreover, the Pd–Ni/HZSM-5 catalyst showed high activities when applying other substrates including anisole, veratrole, guaiacol, benzyloxybenzene, phenethyl phenyl ether, and dibenzyl ether.
研究领域:
催化化学
·
能源化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Qiang Sun,Hongxia Gao,Teerawat Sema,Zhiwu Liang
High energy consumption during the carbon dioxide (CO 2 ) desorption process in amine-based CO 2 capture technology is a crucial hindrance to achieving carbon neutrality. HZSM-5 is one of the most widely reported solid acid catalysts used in primary amine regeneration. This work compared a series of HZSM-5 zeolites with different Si/Al ratios in terms of CO 2 desorption performance. To further enhance catalytic activity, hierarchical HZSM-5 was synthesized by the dealumination and desilication re-assembly method with different acid and alkali concentrations. The experimental results suggested that desilication by modification in sodium hydroxide resulted in a significant improvement of mesoporous surface area. The NaOH-0.4 catalyst could improve the amount of desorbed CO 2 by 40.3% and decrease the relative heat duty by 28.5%. And the cyclic tests revealed that catalytic activity was well preserved in the recycling process. Moreover, the structure and acidity of modification samples were characterized by X-Ray diffraction (XRD), Fourier transforms infrared (FT-IR), Nitrogen adsorption–desorption experiment, temperature programmed desorption of ammonia (NH 3 -TPD), Pyridine-adsorption infrared spectroscopy (Py-IR), and scanning electron microscopy (SEM). The characterization results suggested that the synergistic effect of larger mesoporous surface area and total acid sites was important to enhance catalytic CO 2 desorption performance. These results showed a new understanding of catalyst design for CO 2 capture technology by modifying the structure of the catalyst support.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）