Frontiers of Chemical Science and Engineering
·
2022
·Vol. 16
·期 10
·1505-1513
·
IF 4.803
Abuduwayiti Reyila,Ma Feng-Yun,Fan Xing
Four supported catalysts, nickel and ruthenium on a HZSM-5 support, were prepared by equal volume impregnation and in-situ decomposition of carbonyl nickel. The properties of catalysts were investigated by catalytic hydro-conversion of 2,2′-dinaphthyl ether as the model compound and extraction residue of Naomaohu lignite as the sample under an initial H 2 pressure of 5 MPa and temperature at 150 °C. According to the catalytic hydro-conversion results of the model compound, Ni—Ru/HZSM-5 exhibited the best catalytic performance. It not only activated H 2 into H⋯H, but also further heterolytically split H⋯H into immobile H − attached on the acidic centers of Ni—Ru/HZSM-5 and relatively mobile H + . Catalytic hydro-conversion of the extraction residue from Naomaohu lignite was further examined over the optimized catalyst, Ni—Ru/HZSM-5. Detailed molecular compositions of products from the extraction residue with and without hydrogenation were characterized by Fourier transform infrared spectroscopy and gas chromatography/mass spectrometry. The analytical results showed that the oxygen-containing functional groups in products of hydrogenated extraction residue were obviously reduced after the catalytic treatment. The relative content of oxygenates in the product with catalytic treatment was 18.57% lower than that in the product without catalytic treatment.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Jie Su,Weiyuan Yao,Yue Liu,Zhongbiao Wu
A series of HZSM-5 supported CrO x catalysts at different loadings were prepared by wet impregnation method for catalytic combustion of dichloromethane (DCM) in this paper. The catalytic activity tests indicated that both DCM conversion and product selectivity varied greatly with Cr doping contents. The sample at 2 wt% loading showed the highest DCM conversion, while the selectivity toward CO/CO 2 increased at an elevated CrO x loading. The characterization results revealed that the surface acidity and the chemical states of Cr were strongly affected by the doping content. The surface acidity would decline at an elevated Cr loading owing to the interactions between surface OH groups and chromium ions. And higher surface Cr(VI)/Cr(III) ratios could be observed on the catalysts at lower CrO x doping, leading to the improvement of reducibility. The activity and selectivity of DCM catalytic degradation were found to be highly depended on the balance of surface acidity and redox property. The increased surface acidity could result in the enhancement of dissociated adsorption of DCM, which are beneficial to the catalytic activity. However, higher surface acidity meant lower Cr loading, which might lead the adsorbed intermediates incompletely oxidized and the decrease in CO x selectivity due to the limit redox ability.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2015
·
IF 2.352
Guiquan Zhang,Xin Zhang,Ting Bai,Tengfei Chen,Wentao Fan
The coking kinetics and reaction-regeneration on Zn/HZSM-5 (Zn/HZ) catalyst in the conversion of methanol to aromatics were investigated. The highest initial benzene, toluene and xylene (BTX) yield of ca. 67.7% was obtained on fresh Zn/HZ catalyst, which showed the worst catalytic stability. The cycle of reaction-regeneration significantly modified the texture and acidity of Zn/HZ catalyst, which in turn affected its catalytic performance and coking behavior in methanol conversion to BTX. The residual carbon located on the surface of Zn/HZ catalyst led to the decrease of acid sites and the change on the acid sites distribution, which played an important roles on its activity and deactivation. It was found that the high B/L ratio and the low total acid sites concentration of the Zn/HZ catalyst favored to the high BTX yield and good catalytic stability in methanol conversion.
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
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Hong Tian,Huimin Mao,Jiawei Wang,Yi Cheng
The HZSM-5 zeolite was modified through alkali treatment (NaOH) and metal loading (Ga, Ni), followed by constructing an MCM-41 layer to create a core–shell molecular sieve catalyst. With the feedstock of wheat straw, this work investigated the effects of various catalysts on pyrolysis product distribution and bio-oil composition with a tubular furnace and Py-GC/MS. The results showed that with the alkali-treated HZSM-5, the yield of monocyclic aromatic hydrocarbons (MAHs) in the bio-oil reached 40.35%, with an overall bio-oil yield of 21.16%. Metal-modified zeolites, exhibiting enhanced acidity, further optimized the bio-oil composition, producing an MAH yield of 61.48% and 27.31% bio-oil yield. Bimetal loading with Ga and Ni further enhanced MAH selectivity, delivering an MAH yield of 69.48% and a bio-oil yield of 27.79%. The synergy between Ga and Ni suppressed excessive aromatization and polymerization into polycyclic aromatic hydrocarbons (PAHs), favouring MAH formation. Constructing an MCM-41 layer further promotes the selectivity of MAHs. Compared to uncoated catalysts, those coated with MCM-41 significantly improved monocyclic aromatic yields, achieving the highest MAH yield of 83.61%.
研究领域:
能源化学
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2020
·
IF 7.489
Yaoyu Zhang,Yuxing Wang,Yue Liu,Qingji Ying,Zhongbiao Wu
A sequence of CuCeO x -HZSM-5 composite catalysts at different Cu-Ce loading synthesized by the citric acid complex impregnation method were evaluated for the catalytic oxidation of acetonitrile. Among which, the 2CuCeO x -HZSM-5 sample exhibited the best degradation efficiency. In the temperature range of 225–350 °C, its activity and mineralization rate were approximately 100%, and the N 2 selectivity remained more than 93%. The characterization results revealed that all the samples showed an existence of isolated Cu 2+ species. And more Cu-Ce mixed oxides covered on HZSM-5 at an elevated Cu-Ce content, leading to the enhanced reducibility. In situ DRIFTS results showed that both oxidation and hydrolysis reaction routes proceeded during the degradation of acetonitrile over the composite catalysts. Their synergism was crucial to guarantee both high activity and N 2 selectivity. The highly dispersed CuO x species ensured the superior activity of the 2CuCeO x -HZSM-5 sample. And Cu 2+ exchanged HZSM-5 zeolite would be beneficial to N 2 selectivity owing to the improved internal SCR (Selective Catalytic Reduction) reaction to reduce NO x from oxidation routes. Additionally, the mineralization rate was lowered with the formation of carbonaceous products like CH 4 and CO for the catalysts at low Cu-Ce loading due to the lack of redox capacity.
研究领域:
催化
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Jianfeng Shan,Zheng Chen,Dengfeng Wang,Guangyu Zhang,Sheng Li,Chuan Sun,Dongchao Wang,Caixia Ju,Xuelan Zhang,Lei Li
Catalytic conversion of ethyl levulinate (EL) to γ-valerolactone (GVL) is a pivotal reaction in biomass conversion. Here, Pd/CoO x was studied and showed much higher EL hydrogenation reactivity than other Pd based catalysts. Further investigation revealed that EL conversion increased linearly with PdCo alloying degree elevating, indicating that PdCo alloy is ascribed to the superior reactivity of Pd/CoO x . Interestingly, Pd/CoO x with low Pd loading also exhibited excellent hydrogenation performance, and surface enrichment of Pd was identified as the main reason. Additionally, employing HZSM-5 as a co-catalyst not only accelerated ethyl 4-hydroxypentanoate lactonization, but also dramatically improved the stability of Pd/CoO x . As a result, a 99.1 % yield of GVL was achieved by the synergistic catalysis of HZSM-5 and Pd/CoO x containing 0.58 wt% Pd, which is comparable with the best catalyst ever reported in alkyl levulinate hydrogenation to GVL. Furthermore, the insights gained from this work have broad potential applications in biomass hydrogenation.
研究领域:
生物质能
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2021
·Vol. 13
·期 3
·2017-2028
·
IF 4.987
Zhang Zhenshu,Du Boyu,Zhu Hongwei,Chen Changzhou,Sun Yang,Wang Xing,Zhou Jinghui
To improve lignin depolymerization reaction performance of HZSM-5 zeolite catalyst, we reported the effective catalytic depolymerization of rice husk lignin (RHL) to lignin phenolic monomer (LP) products over the different Si/Al mole ratios of HZSM-5 zeolite catalyst. Firstly, five samples comprising different Si/Al mole ratio of HZSM-5 zeolite catalyst were prepared by the physical method. The X-ray powder diffraction (XRD), scanning electron microscope (SEM), Brunauer–Emmett–Teller (BET), pyridine adsorption Fourier transform infrared spectroscopy (FT-IR), and temperature-programmed desorption of ammonia (NH 3 -TPD) were used to characterize various catalysts. Secondly, gas chromatography–mass spectrometry (GC-MS), 2D heteronuclear single quantum coherence (2D-HSQC), and gel permeation chromatography (GPC) were used to characterize various catalytic depolymerization products. The effect of different Si/Al molar ratios on the lignin conversion to LP products and the structural changes of residual lignin were analyzed. Finally, according to the results of LP products, we discovered that after the use of different Si/Al molar ratios of HZSM-5 zeolite catalysts, the content of acid in the different catalysts which increased with decreasing the Si/Al mole ratios. Among them, the A4P PM products (A4P: having a saturated or unsaturated aliphatic side chain in C4 position) increased from 0.58% (SA560, Si/Al: 560) to 1.83% (SA70, Si/Al: 70), the C6P PM products (C6P: having no side chain in C4 position of G, S, and H structure) increased from 1.53% (SA560, Si/Al: 560) to 3.41% (SA70, Si/Al: 70). Finally, the highest 6.05% PM products yield appeared in the SA70 (Si/Al: 70) catalytic system. It is worth noting that PM products produced by this HZSM-5 zeolite catalyst SA70 have great potential to be a promising renewable alternative to fossil resources. Graphical abstract
研究领域:
催化化学
·
生物质能转化
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Binbin Chen,Hong Tian,Zhen Zhou,Yanni Xuan,Zhijie Wang,Siying Liu
A combined pretreatment of straw was carried out using acid washing and torrefaction methods. Metal-modified HZSM-5 core–shell molecular sieves were prepared by loading Zn (2, 4, and 6 wt%) and Ni (6, 8, and 10 wt%) on HZSM-5 molecular sieves and introducing MCM-41 core–shell structure. PY-GC/MS and a tubular furnace were employed to study the effects of pretreatment conditions and catalysts on the product composition distribution during wheat straw catalytic pyrolysis. XRD, SEM, BET, TPD and ICP were used to characterize the catalyst performance. It was found that the combined acid washing and torrefaction pretreatment reduced the oxygenated compounds in the bio-oil from straw catalytic pyrolysis and increased the bio-oil yield to 29.37 %. The incorporation of modified catalysts promoted the deoxygenation, zwitterionization and aromatization reactions during the straw-catalyzed pyrolysis. The monometallic loading of 4%Zn/HZ and 8%Ni/HZ catalyzed acid washing and torrefaction straw pyrolysis resulted in 54.2 % and 57.06 % yields of MAHs and 42.86 % and 38.58 % yields of BTX in bio-oil, respectively.Compared with the monometallic loading, 4%Zn8%Ni/HZ further optimized the bio-oil compositional distribution, with a MAHs yield of 64.76 %, a BTX yield of 54.69 %, and a deoxygenation performance of 81.34%.MCM-41-coated HZSM-5 produces a large mesoporous structure with channels with sufficient transport capacity, accelerating the cleavage of various types of oxygen-containing compounds in the bio-oil into smaller molecules for better conversion into aromatics. The 4%Zn8%Ni/H@M catalyst achieved a MAHs yield of 72.68 % and BTX yield of 63.43 % in the bio-oil during pyrolysis of acid-washed and torrefied wheat straw, with oxygen removal efficiency reaching 85.37 %. Therefore, the combination of feedstock pretreatment and metal-modified core–shell HZSM-5 molecular sieve could synergistically optimize both compositional distribution and production yield of bio-oil derived from biomass pyrolysis.
研究领域:
催化化学
·
生物质能源
·
材料科学
·
环境工程
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2022
·
IF 8.047
Xin-Xin Fu,Jian-Peng Li,Zhuo-Qian Li,Yan Liu,Chen-Xiao Feng,Hai-Yang Wang,Zhi-Peng Zhao,Qiao-Yun Liu,Zhong-Yi Liu,Zhi-Kun Peng
Biomass is a promising renewable carbon resource, and bio-based platform molecules such as furan derivatives play an important role in the green manufacturing of high value-added chemicals. Of these, the conversion of 2-methylfuran (2-MF) to 3-acetyl-1-propanol (3-AP) over a bifunctional catalyst has attracted significant interest. However, bifunctional catalysts prepared by traditional method suffer from poor catalytic performance and limited stability due to the agglomeration of metal NPs. Here, Pd@HZSM-5, in which Pd NPs were encapsulated in HZSM-5 in situ showed improved stability and 3-AP yield. The highest yield of 3-AP (90.6%) to date was obtained with a nearly 100% conversion of 2-MF. The catalytic performance over a series of Pd@Zeolite confirms the superiority of the encapsulation effect, which is ascribed to the optimal adjustment of metal/acid balance. The Pd@HZSM-5 catalyst displayed excellent stability due to the encapsulation structure, which restricts the Pd NPs agglomeration. The highest yield of 3-AP was obtained at a high concentration of 2-MF (60%), which implies a promising strategy for the green industrial manufacture of 3-AP. This work reports a new bifunctional catalytic system for the green synthesis of 3-AP from 2-MF, thus stimulating the downstream biomass market.
研究领域:
催化化学
·
生物质能
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2023
·
IF 5.5
Shaoqing Wang,Yan Jiao,Zhihe Li,Zhen Wan,Yu Han,Weiming Yi
In this paper, a surface encapsulation method has been developed to synthesize the HZSM-5 @Al-KIT-6 hierarchical zeolites, due to the poor mono-aromatic hydrocarbons (MAHs) selectivity and rapid coke deactivation during the catalytic upgrading lignin pyrolysis vapors. Results showed that the acidity and accessibility of HZSM-5 @Al-KIT-6 hierarchical zeolite can be modulated by changing the TEOS/HZSM-5 mass ratio during catalyst synthesis. The three-dimensional (3-D) cubic mesoporous shell can capture the bulky phenolic oligomers and pre-crack for further reforming. The highest MAH content (44.03%) and lower polycyclic aromatic hydrocarbons (PAHs) (23.79%) were produced when the TEOS/HZSM-5 mass ratio was 1.0. The hierarchical zeolites improved the yield of xylenes due to the enhanced alkylation reaction. In addition, the micro-mesoporous highway reduced the formation of coke deposition. The catalytic mechanism of hierarchical zeolites was then proposed based on the obtained results. This study provides a reference for pilot-scale experiments for the catalytic upgrading lignin pyrolysis vapors.
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
AUSTRALIAN JOURNAL OF CHEMISTRY
·
2016
·Vol. 70
·期 6
·691-698
·
IF 1.427
Yu Shen,Fumin Wang,Chaoqun Yang,Xubin Zhang
Hierarchical HZSM-5 were synthesised by controlled desilication in alkaline medium and characterised by field-emission scanning electron microscopy, X-ray diffraction, transmission electron microscopy, inductively coupled plasma–atomic emission spectrometry, N2 adsorption–desorption, and Fourier transform infrared spectroscopy. The catalytic performance of HZSM-5 towards the selective oxidation of 2,3,6-trimethylphenol by H2O2 was evaluated. Recyclability tests were also carried out. The results showed that 2,3,5-trimethyl-1,4-benzoquinone was produced in high yields (i.e. 90 %), corresponding to a 2,3,6-trimethylphenol percentage of 98 %. The N2 adsorption–desorption and XRD studies suggested that mesopores with an average size of 5 nm were produced and that the structural character of HZSM-5 was preserved after desilication. Transmission electron microscopy analysis of the spent catalyst indicated good stability of the hierarchical structure. The Fourier transform infrared spectroscopy studies revealed the development of acid sites. The combined results suggested that the nature of the solvent, intrinsic acidity, and shape selectivity of the hierarchical structure of the catalyst ensured high catalytic properties.
研究领域:
化学工程
·
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2024
·
IF 9
Bingshuo Li,Aorong Ding,Tianhua Yang,Zhuo Wang,Haijun Zhang,Xingping Kai,Rundong Li
Hydrodeoxygenation (HDO) of phenols has significant potential for the synthesis of cycloalkane. In this study, a Ni-based magnetic molecular sieve catalyst, Ni/HZSM-5@SiO 2 @Fe 3 O 4 , was carefully prepared and systematically characterized using various analytical methods. A screening of the HDO reaction conditions was carried out using a typical phenolic compound of 4-ethylphenol. Under the optimal reaction conditions (240 °C, 3 h) with n-dodecane as the solvent, the 6 % Ni/HZSM-5@SiO 2 @Fe 3 O 4 catalyst showed excellent performance, achieving a 4-ethylphenol conversion of 59.3 % and an ethylcyclohexane selectivity of 85.1 %. In comparison to conventional Ni/HZSM-5, the magnetic micromesoporous molecular sieve catalyst exhibited superior catalytic activity, alkane selectivity and recyclability, with a catalyst recovery ratio of 95 %. Furthermore, the effect of liquid-solid mass transfer efficiency on the ethylcyclohexane selectivity considering of the stirring speed was studied, and the selectivity was increased from 81.6 to 85.1 % when the speed was increased from 400 to 600 rpm. This finding was further substantiated by Fluent numerical simulation. To elucidate the HDO pathway of 4-ethylphenol on Ni/HZSM-5@SiO 2 @Fe 3 O 4 , a comprehensive reaction pathway was proposed, providing insights into the catalytic mechanism.
研究领域:
催化化学
·
能源化学
✓ 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）