CATALYSIS TODAY
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2015
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IF 3.893
Liangguang Chen,Huiwen Li,Junying Fu,Changlin Miao,Pengmei Lv,Zhenhong Yuan
A series of Ni/HZSM-5 catalysts with different Ni loading and Si/Al ratios were prepared by incipient wetness impregnation. The physicochemical properties of the catalysts were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 -adsorption, temperature-programmed desorption of ammonia (NH 3 -TPD), and thermogravimetric (TG) analysis. Moreover, their catalytic performance was investigated for the hydroprocessing of long-chain unsaturated fatty acid methyl esters (FAMEs) to renewable alkane fuels using a high-pressure fixed bed reactor system with a facility for online analysis. The different Ni loading and Si/Al ratios of the catalysts, as well as the influence of reaction conditions such as temperature, pressure, H 2 /oil molar ratio, and liquid hourly space velocity (LHSV), were studied in detail. The NiO aggregates dispersed on the surface of the support clearly increased the acidity after H 2 reduction, thus significantly affecting the catalytic performance. Temperature and pressure played crucial roles in the conversion of FAMEs and selectivity for gasoline or jet or diesel alkane. Hydroprocessing over 10 wt% Ni/HZSM-5 (Si/Al = 25) at 280 °C, a H 2 pressure of 0.8 MPa, an LHSV of 4 h −1 , and with a highly purified H 2 /oil molar ratio of 15 led to a high selectivity of 88.2% for C 5 –C 18 liquid alkanes, which includes 8% of gasoline alkane, 32.5% of jet alkane and 47.7% of diesel alkane, along with appropriate isomerization selectivity of 27.0%, while the conversion of FAME reached 85.1%. To demonstrate the potential of this catalyst for practical applications, its stability in the hydroprocessing of FAMEs was also investigated. The conversion of FAMEs decreased to 30.1% over 10 wt% Ni/HZSM-5 (Si/Al = 25) after operation for 80 h. Catalyst deactivation was predominantly caused by the deposition of carbon which causes blockage of the pores for FAMEs as evidence from TG analysis.
研究领域:
能源化学
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催化材料科学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Jinye Hu,Wenguang Zhou,Yunpu Wang,Haiwei Jiang,Jiabo Wu,Ting Luo,Mengjiao Wang,Weixin Wang,Qi Wang,Yuhang Hu,Liangliang Fan
HZSM-5 widely used for the catalytic pyrolysis of biomass exhibits the drawbacks of high diffusion resistance and large coke production. To effectively enhance the catalytic efficiency and alleviate the coke deposition, a novel promising catalyst, HZSM-5 coated activated carbon (HZSM-5@AC), was prepared for the first time for in-line upgrading the pyrolysis products of soybean straw. Various catalysts including HZSM-5, activated carbon, and the HZSM-5@AC catalysts with different HZSM-5 to activated carbon mass ratios were characterized. The results showed that the HZSM-5 was successfully coated on the surface of activated carbon and the addition of activated carbon introduced a mesoporous structure and more acidic sites to the catalyst. The catalytic performance on the biomass conversion showed that the catalyst with HZSM-5-to-activated carbon mass ratio of 18:5 (18HZSM-5@5AC) had the highest catalytic efficiency on the conversion of biomass into aromatics with a selectivity of 99.5%, including 75.68% of benzene, toluene, and xylenes (BTX) with a yield of 74.68 mg/g. Moreover, a possible pathway for HZSM-5@AC catalyzed biomass pyrolysis was proposed through analyzing the conversion of model compounds. The catalyst cycling experiments demonstrated the higher stability of HZSM-5@AC than the parent HZSM-5 and activated carbon. TG, FTIR, Raman and SEM showed that the spent HZSM-5@AC was hardly structurally changed with a low coke yield of 0.08%. However, the spent HZSM-5 was partly structurally deactivated by large aromatic ring systems with a coke yield of 3.74%. SEM results also showed that a large amount of polymerized material encapsulated the surface of the spent HZSM-5.
研究领域:
能源化学
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催化材料科学
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产品关联
DOI
高影响因子
NANO
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2016
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IF 0.951
Wei Li,Gang Ni,Jing Li,Ying Han
BiOI/HZSM-5 composites were synthesized via a facile and environmentally-benign hydrothermal method. The crystalline structures and morphologies of the powder have been characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The photocatalytic activity of samples was tested for degradation of methylene blue (MB) and Rhodamine B (RhB) dye under simulated solar light irradiation. The degradation rate of MB and RhB by BiOI/HZSM-5 composite photocatalysts respective reach 99.6% and 98.6% under visible light irradiation, BiOI/HZSM-5 exhibited the highest photocatalytic performance when compared with pure BiOI.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
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2019
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IF 2.938
Liqin Wang,Heqin Guo,Qiang Wang,Bo Hou,Litao Jia,Jinglei Cui,Debao Li
Furfural, generally achieved from hemicelluloses and its derived pentose, is a high value-added product. The formation of furfural from cellulose and hexose remains challenging. The acid sites in zeolites are the major active sites for preparing furfural from hexose. The catalytic performance of zeolites can be improved by increasing the number of active sites for the preparation of furfural. In this work, HZ-Na free-m and HZ-Na-m zeolites were prepared through without or with adding Na + ions in the mother gels, respectively. GHB (hydrolysate of GBL) was the active site for the formation of acyclic fructose precursor (Intermediate 2). Acyclic fructose production and the following dehydration for producing furfural were favored by the middle strong and strong Brønsted acids in the channels of HZSM-5. Meanwhile, middle strong and strong Brønsted acids were favored the production of HMF from fructose and furfural from xylose. The exterior weak Lewis acid of HZSM-5 could promote the formation of soluble oligomers. The soluble oligomers were composed by HMF and furfural through condensation, etherification, nucleophilic attack and electrophilic attack. HMF molecule was easy to participate in the production of soluble oligomers than furfural molecule over exterior weak Lewis acid of HZSM-5.
研究领域:
化学工程
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催化科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2020
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IF 3.905
Chaoyue Shen,Xiying Jia,Yifei Chen,Licong Lu,Fangqi Wang,Yi Wei,Fengwen Yu
Molten carbonate pyrolysis is proposed to convert digestate (DE) into biobased monophenols coupled with a metal-modified HZSM-5 catalyst. The results indicated that Fe/HZSM-5 was the most suitable catalyst for this process. The optimum reaction conditions for the process were WHSV = 15 h −1 at a pyrolysis temperature of 430 °C and a catalytic cracking temperature of 475 °C, and 79.22 % of monophenol components were achieved in the bio-oil. A kinetic study on the digestate with carbonates indicated that the alkali metal ion in the molten carbonates attached to the β-O-4 bonds and branch methoxy group of lignin, which promoted the removal of these functional groups, resulting in a reduction in the activation energy during monophenol generation. The Fe/HZSM-5 catalyst reinforced the generation of monophenol compounds in both concentration and yield. Compared with molten carbonate pyrolysis, the Fe on the catalyst not only benefited the breaking of β-O-4 bonds and methoxy groups of lignin but also lowered the temperature during molten carbonate pyrolysis to minimize the secondary cracking of phenolic compounds.
研究领域:
生物化学
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催化反应工程
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2020
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IF 3.573
Ying-Bo Zhu,Jia Guo,Yu-Long Ma,Yuan-Yuan Li
The production of high-value-added chemicals from the degradation of real lignin still has been an unresolved issue. In this study, a two-step strategy was proposed to obtain n-hexanol from alkali lignin, and high conversion of alkali lignin and selectivity of n-hexanol were achieved. The deoxygenation performance of the synthesized Ni-HZSM-5 catalyst, modified by Ca, was efficiently improved. At first, through the deoxygenation of alkali lignin via Ni/CaO-HZSM-5, the C–O bonds of the material were broken effectively and 44% degree of deoxygenation (DOD) was obtained. Second, n-hexanol was selectively produced over the Ni/HZSM-5 catalyst from the liquid product obtained by the first step. The efficiency of deoxygenation (DOD) was attained at 71%, and the heat value increased to 51.6 MJ/kg from 19.9 MJ/kg after the two-step strategy. This strategy showed a high catalytic effect to produce n-hexanol from alkali lignin using Ni/CaO-HZSM-5 and Ni/HZSM-5 catalysts and revealed a superior advantage in the hydrodeoxygenation of real lignin to form high additional value chemicals.
研究领域:
化学工程
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可再生资源利用
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
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IF 10.652
Yunpu Wang,Linyao Ke,Yujie Peng,Qi Yang,Yuhuan Liu,Qiuhao Wu,Yujie Tang,Haibin Zhu,Leilei Dai,Zihong Zeng,Lin Jiang,Roger Ruan
In view of the poor selectivity of aromatic hydrocarbons in bio-oil from biomass pyrolysis and the high pressure drop and rapid coking and deactivation of catalyst in industrial scale, a microwave-driven HZSM-5@SiC ceramic foam has been constructed, and applied to the ex-situ catalytic fast pyrolysis of soapstock to improve the content of aromatic hydrocarbons in bio-oil. The effects of different catalysts and heating modes and mass ratios of HZSM-5@SiC ceramic foam to soapstock on the distribution of pyrolysis products have been investigated. In addition, combined with the comparison of microwave and electric heating, the deactivation characteristics of HZSM-5@SiC ceramic foam have been studied. Finally, the process of preparing aromatic oil by microwave-driven catalytic pyrolysis of soapstock was discussed. Experimental results indicate that compared with HZSM-5, HZSM-5@SiC ceramic foam has a higher yield of bio-oil and higher aromatization activity. Under microwave heating, the relative content of aromatic hydrocarbons increases from 25.18% to 100% when the mass ratio of HZSM-5@SiC ceramic foam to soapstock increases from 0:1 to 1:1. Compared with electric heating catalysis, HZSM-5@SiC ceramic foam has the lowest yield of coke under microwave heating. After five consecutive uses, it still maintains more than 90% catalytic activity and has higher stability, which provides a scientific basis for the pilot scale experiments of soapstock catalytic pyrolysis.
研究领域:
能源与环境科学
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化学工程
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产品关联
DOI
高影响因子
ACS Catalysis
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2021
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IF 13.084
Ting Wang,Yuebing Xu,Yufeng Li,Lei Xin,Bing Liu,Feng Jiang,Xiaohao Liu
Conversion of syngas into aromatics via the Fischer–Tropsch (FT) route provides a promising way to supply the value-added chemicals. However, it is still a great challenge to achieve controllable aromatics selectivity with good stability. Herein, we report the Na-mediated bimetallic Fe–Ni catalyst simply particle mixed with HZSM-5, which can boost the stable and selective production of aromatics from the syngas. In detail, FeNiOx(5:1)-0.41Na exhibits quite stable catalytic activity with notably higher selectivity to light α-olefins (C2=–C4=) compared to α-Fe2O3-0.75Na. Various characterizations suggest that an appropriate addition of Ni with Na substantially regulates iron carbide formation and suppresses carbon deposition owing to the electron donation of Fe to Ni reducing CO adsorption and dissociation. Interestingly, extra Na results in remarkably increased selectivity to C1o–C4o, despite the fact that Na shows the ability to suppress hydrogenation. Both characterizations and density functional theory (DFT) calculations demonstrate that the addition of Na weakens the Fe–Ni interaction and reduces electron transfer from Fe to Ni, which promotes C1o–C4o formation as Ni tends to reflect its intrinsic catalysis. DFT calculations confirm that the adsorbed CH2 species at the Ni–Fe interface prefers to undergo coupling to form C2H4, and the formed C2H4 spontaneously desorbs from the surface, indicating that the formation of lower olefins is favorable and further chain growth is inhibited. This could be attributed to the fact that the accumulated electron at the Ni–Fe interface weakens the binding strength of CH2 and C2H4 species because of electronic repulsion. Furthermore, the effects of FT product distribution on aromatics formation were also investigated. FeMnOx(5:1)-0.40Na produces longer olefin-rich hydrocarbons in C5+ owing to oxygen vacancy-assisted CO dissociation, leading to highly branched monocyclic aromatics and faster HZSM-5 deactivation because of increased coking from the isomerization–hydrocracking of long hydrocarbons. In contrast, FeNiOx(5:1)-0.41Na-HZSM-5 produces major light aromatics about 65.7% including toluene, ethyl-benzene, and xylene in total aromatics with about 98.6% aromatics in the liquid phase, which benefits from the fact that FeNiOx(5:1)-0.41Na makes shorter hydrocarbons in C5+ and/or Ni metal has a strong ability of H2 dissociation to provide atomic H spillover onto HZSM-5. Thus, HZSM-5 also shows improved stability. Note that the mixed catalysts with a high Na content indicate a substantial Na+ migration to increase light α-olefins in the gas phase owing to suppress H-transfer reaction. This study provides deep insights into how to develop stable and selective iron-based catalysts for the production of FT products and its further conversion into value-added light aromatics.
研究领域:
催化化学
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材料科学
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能源化学
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产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
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2020
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IF 7.539
Kai Li,Guan Zhang,Ze-xiang Wang,Bin Hu,Qiang Lu
An efficient process was developed to selectively produce monocyclic aromatic hydrocarbons (MAHs) from ex-situ catalytic fast pyrolysis (CFP) of pine assisted with calcium formate (CF) over bimetal-modified HZSM-5. Mo and another metal (Mg, Ga or Zn) were used to modify the HZSM-5, and the as-synthesized bimetal-modified HZSM-5 catalysts were utilized for both pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and lab-scale CFP tests with CF as a hydrogen donor to selectively obtain MAHs. The results revealed that the presence of CF and Mg-Mo modified HZSM-5 (0.5Mg1Mo/HZ) exhibited excellent capability for MAHs production with tiny generation of polycyclic aromatic hydrocarbons (PAHs). The maximum MAHs yield attained 12.79 wt% at 650 °C from Py-GC/MS with the CF-to-pine (CF-to-PN) ratio of 3 and catalyst-to-pine (CA-to-PN) ratio of 11, and became 9.67 wt% from lab-scale device with CF-to-PN and CA-to-PN ratios of 0.5 and 4, respectively. In addition, compared with HZSM-5, 0.5Mg1Mo/HZ possessed better anti-deactivation ability.
研究领域:
化学工程
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能源科学
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生物质转化
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产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
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2021
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IF 5.706
Xiaochao Xian,Mengjun He,Yakai Gao,Yi Bi,Yirong Chu,Jun Chen,Lichun Dong,Jin Wang,Shuo Zhao
Reducing the acid density and strength of HZSM-5 zeolite are typical strategies to inhibit coke deposition during catalytic cracking reactions. Herein, direct titration of HZSM-5/H 2 O suspension using dilute NaOH aqueous solution at room temperature was introduced to neutralize excessive Brønsted acid sites of HZSM-5 zeolite (Si/Al = 25). SEM, XRD, N 2 adsorption and n -propylamine temperature-programmed decomposition confirmed that simultaneous acid strength weakening and acid density reducing were achieved without obvious influence on crystalline or textural property. The evolution of the surface charge during the titration process tracked by Zeta-potential measurement reveals that the mechanism of such neutralization is: liquid phase neutralization between H + and OH − & solid phase ion exchange between Na + and H + . Supercritical catalytic cracking of n -dodecane over a series of partial neutralized HZSM-5 catalysts showed that moderate neutralization can enhance the conversion of n -dodecane by alleviating both the coke amount and harmfulness per unit mass of coke.
研究领域:
化学工程
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催化材料
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
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2025
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IF 6.3
Jun-Feng Lu,Huan Wang,Yi Zhou,Xue-Ying Mao,Xiao-Qian Feng,Shuang Wang,Yong-Hua Zhao
Background Rhodamine B (RhB) poses a significant threat to aquatic ecosystems. While Fenton oxidation process is promising approach for RhB degradation, the conventional Fenton reaction has the narrow pH range and poor reusability. To overcome these, this study developed Fenton-like system with Fe-Cu/HZSM-5 catalyst for effective RhB degradation. Methods A series of Fe x Cu 5-x /HZSM-5 catalysts (x represents the molar ratio of Fe to Cu) were prepared by impregnation. These catalysts were integrated with H 2 O 2 to construct Fenton-like system for the degradation of RhB. The catalysts were characterized by XRD, NH 3 -TPD, XPS, FT-IR, and N 2 adsorption-desorption at low temperature techniques. Significant findings Among the tested catalysts, Fe 3 Cu 2 /HZSM-5 exhibited optimal performance, achieving near-complete RhB degradation (∼100%) under the condition of 45 °C, 5.3 mM/L H 2 O 2 , 3.0 g/L catalyst dosage, and broad pH range (2–5). Mechanistic studies confirmed that hydroxyl radicals (·OH) were the primary oxidants responsible for RhB degradation in Fenton-like system. Under ·OH attacking, RhB underwent a series of reactions such as N-deethylation and disruption of the conjugated structure and was eventually mineralized into CO 2 and H 2 O. Overall, a novel Fe-Cu/HZSM-5 catalyst was developed to address the limitations of the traditional Fenton reaction, providing valuable insights for future research in this field.
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2021
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IF 9.229
Jiayu Feng,Fei Wang,Chi Wang,Kai Li,Xin Sun,Ping Ning
In this study, an NH3 plasma-treated Cu/HZSM-5 sorbent was introduced to simultaneously remove H2S and PH3 in low-temperature and low-oxygen environments. The effects of the Cu loading amounts, modification methods, and plasma-treatment conditions on the adsorption–oxidation performance of the sorbents were investigated. From the performance test results, the sorbent treated by NH3 plasma with the specific energy input (SEI, electrical input energy to the unit volume of gas) value of 1 J·mL–1 (Cu/HZSM-5-[S1]) was identified as having the highest breakthrough capacities of 108.9 mg S·g–1 and 150.9 mg P·g–1 among all of the materials tested. After three times of regeneration, the sorbent can still maintain the ideal performance. The results of Fourier transform infrared (FT-IR) spectroscopy and CO2 temperature-programmed desorption (CO2-TPD) indicated that the NH3 plasma treatment can introduce amino groups (functional groups) onto the sorbent surface, which greatly increases the number and strength of the basic sites on the sorbent surface. Results of N2 adsorption/desorption isotherms and scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS) showed that the morphology of the sorbent changed after the plasma treatment, which exposed more active sites (copper species). In situ IR spectra showed that the amino groups are continuously consumed during the reaction process, indicating that these amino groups can help sorbents to capture gas molecules. Moreover, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses indicated that CuO is the main active species and the consumption of CuO and accumulation of the reaction products on the surface and inner pores of the sorbent are the primary reasons for the deactivation of the sorbent.
研究领域:
环境科学
·
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）