ENERGY & FUELS
·
2022
·
IF 4.654
Xiuhong Zhang,Dong Wang,Xiao Chen,Longwei Meng,Changhai Liang
The hydrogenation of polycyclic aromatic hydrocarbons (PAHs) over highly efficient and stable catalysts to fine chemicals and intermediates for producing chemical materials is an effective approach to realize the high value-added utilization of coal tar and slurry oil. Herein, two kinds of Al2O3-supported Pt and Rh catalysts are synthesized by strong electrostatic adsorption (SEA) and used to catalyze the hydrogenation of anthracene. Compared with the traditional catalysts synthesized by wet impregnation, the Pt/Al2O3-SEA and Rh/Al2O3-SEA catalysts have smaller active metal particle sizes and higher dispersion, which can expose more active centers, showing higher catalytic activity. Interestingly, anthracene may be preferentially adsorbed on the surface of the Pt/Al2O3 catalyst in a parallel manner but on the surface of the Rh/Al2O3 catalyst in a lateral manner, which leads to the different hydrogenation routes. 9,10-Dihydroanthracene is an initial product for the hydrogenation of anthracene, which is rearranged into tetrahydroanthracene and subsequently hydrogenated to symmetrical octahydroanthracene (sym-OHA) over the Pt/Al2O3 catalyst. The high selectivity to sym-OHA (93%) with the conversion of anthracene near 100% can be achieved in the hydrogenation of anthracene at 240 °C and 7 MPa for 10 h. Additionally, due to the strong anchoring effect, the Pt/Al2O3-SEA catalyst shows high stability for six cycles. This work supplies a new tactic to develop high-performance catalysts for selective hydrogenation of PAHs to important monomers for synthesizing chemical materials.
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
Frontiers in Chemistry
·
2022
·
IF 5.545
Huang Meng,Huang Wenbin,Li Anqi,Yang Han,Jia Yijing,Yu Zhiqing,Xu Zhusong,Wang Xiaohan,Zhou Yasong,Wei Qiang
Experiments were carried out to research the different contents of Ga2O3 modification effects on the hydrodesulfurization (HDS) performance of 4,6-dimethyldibenzothiophene (4,6-DMDBT) catalyzed by the stepwise impregnation method. Characterization techniques such as XRD, BET, HRTEM, NH3-TPD, and Py-FTIR were performed to determine the effects of each modification of the catalyst by Ga on the properties of the prepared supports and catalysts. The catalytic effect of gallium is reflected in the fact that the empty d-orbitals of Ga elements participate in the formation of molecular orbitals in the active center and change their orbital properties, thus generating a direct desulfurization active phase suitable for complex sulfides for endpoint adsorption. The characterization results indicated that the introduction of Ga2O3 with appropriate content (2 wt.%) promoted Ni and Mo species to disperse uniformly and doping of more Ni atoms into the MoS2 crystals, which also increased the average stacking number and the length of MoS2. As a result, more NiMoS active phases were favored to form in the system. The specific surface area and the amounts of acid sites were increased, facilitating the adsorption of reactant molecules and the HDS reactions. The HDS results also suggested the effects of Ga modification play a very important role in the catalytic performance of the corresponding catalysts. The catalyst Ga–Ni–Mo/Al2O3 exhibited the highest conversion rate towards 4,6-DMDBT HDS when the amount of Ga2O3 loading was 2 wt.% with an LHSV of 2.5 h−1 at 290°C and Ga modification also can effectively improve the direct desulfurization (DDS) route selectivity in varying degrees.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 53
·80399-80410
·
IF 5.19
Shu Xinpeng,Bi Huaqi,Wang Jun,Yang Jiaxin,Wang Jue,Liu Guangqing,Su Bensheng
Catalytic ozonation with supported metal oxides is a promising strategy for addressing refractory pollutants in wastewater. In this study, γ-Al 2 O 3 supported MnO x -CeO x catalysts (MC 1 , MC 2 , and MC 3 ) obtained at different calcination temperatures (400 °C, 550 °C, and 700 °C) were applied as effective catalysts for ozonation and explored the feasibility of the treatment of oxytetracycline (OTC) wastewater. Comparatively, the MC 2 possessed the highest molar ratios of Mn 3+ /Mn 4+ (1.60) and Ce 3+ /Ce 4+ (0.96), the largest surface area (273.8 m 2 g −1 ) with a petal-shaped structure, and most abundant surface hydroxyls (3.78 mmol g −1 ). These physicochemical characteristics benefited the surface reaction and resulted in the acceleration of ozone decomposition, electron transfer, and •OH generation, thereby improving the catalyst’s adsorption ability and catalytic activity. The combination with MC 2 increased the OTC and COD removal of the ozonation process from 59.1% and 29.0% to 94.7% and 83.3% in 25 min, respectively. By employing electron paramagnetic resonance (EPR) and radical quenching experiments, it was verified that •OH species generation promoted the mineralization of OTC. The possible degradation pathways of OTC were investigated through mass spectrometry, and the route consisted of dehydration, deamination, and demethylation. Moreover, during a 12-day continuous experiment, MC 2 catalyst exhibited excellent reusability and catalytic stability, with COD removal efficiencies above 80%.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Jiayu Feng,Ping Ning,Kai Li,Xin Sun,Chi Wang,Lijuan Jia,Maohong Fan
The conventional Haber–Bosch NH3 synthesis process requires high temperatures and pressures, resulting in a high carbon footprint and the need to develop alternative NH3 synthesis methods. Accordingly, plasma-based and γ-Al2O3-catalyzed NH3 synthesis from H2O (a hydrogen source) and air/N2 (a nitrogen source) was studied under low temperature and low pressure conditions. The experimental results show that NH3 can be synthesized with air/N2 and H2O, although byproducts such as NO and N2O are also formed. The NH3 formation rate resulting from the use of N2 and H2O is higher than that of air and H2O. Increasing specific energy input (SEI) can increase the NH3 formation rate. Nevertheless, the energy efficiency of NH3 synthesis technology first increases and then decreases with SEI. An NH3 formation rate of 2.92 μmol h–1 g–1 was achieved with an SEI of 11.68 J mL–1 and energy efficiency of 5.10 mg kW–1 h–1 (1.28 mg kWh–1g–1), when wet air at a flow rate of 200 mL min–1 was introduced into the dielectric barrier discharge (DBD) reactor, which was lower than that (4.30 μmol h–1 g–1) attained with N2 + H2O under an SEI of 11.50 J mL–1 and energy efficiency of 7.63 mg kW–1 h–1 (1.91 mg kWh–1g–1). Additionally, the γ-Al2O3 catalyst exhibited good stability. Different results show that plasma-based and γ-Al2O3 catalyzed NH3 synthesis technology is promising.
研究领域:
化学工程
·
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 12
·2753
·
IF 4.2
Yongzhen Gao,Wenjing Yi,Jingyi Yang,Kai Jiang,Tao Yang,Zhihan Li,Meng Zhang,Zhongyi Liu,Benlai Wu
The selective hydrogenation of the biomass platform molecule furfural (FAL) to produce furfuryl alcohol (FA) is of great significance to alleviate the energy crisis. Cu-based catalysts are the most commonly used catalysts, and their catalytic performance can be optimized by changing the preparation method. This paper emphasized the effect of calcination atmosphere on the performance of a Cu/Al2O3catalyst for the selective hydrogenation of FAL. The precursor of the Cu/Al2O3catalyst prepared by the ammonia evaporation method was treated with different calcination atmospheres (N2and air). On the basis of the combined results from the characterizations using in situ XRD, TEM, N2O titration, H2-TPR and XPS, the Cu/Al2O3catalyst calcined in the N2atmosphere was more favorable for the dispersion and reduction of Cu species and the reduction process could produce more Cu+and Cu0species, which facilitated the selective hydrogenation of FAL to FA. The experimental results showed that the N2calcination atmosphere improved the FAL conversion and FA selectivity, and the FAL conversion was further increased after reduction. Cu/Al2O3-N2-R exhibited the outstanding performance, with a high yield of 99.9% of FA after 2 h at 120 °C and an H2pressure of 1 MPa. This work provides a simple, efficient and economic method to improve the C=O hydrogenation performance of Cu-based catalysts.
研究领域:
催化化学
·
能源化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Sciences
·
2021
·
IF 5.565
Chang Cui,Yan Zhang,Wenpo Shan,Yunbo Yu,Hong He
Alumina supported Pd catalyst (Pd/Al 2 O 3 ) is active for complete oxidation of methane, while often suffers transient deactivation during the cold down process. Herein, heating and cooling cycle tests between 200 and 900°C and isothermal experiments at 650°C were conducted to investigate the influence of NO x on transient deactivation of Pd/θ-Al 2 O 3 catalyst during the methane oxidation. It was found that the co-fed of NO alleviated transient deactivation in the cooling ramp from 800 to 500°C, which was resulted from the in situ formation of NO 2 during the process of methane oxidation. Over the Pd/θ-Al 2 O 3 , thermogravimetric analysis and O 2 temperature programmed oxidation measurements confirmed that transient deactivation was due to the decomposition of PdO particles and the hysteresis of Pd reoxidation, while the metal Pd entities were less active for methane oxidation than the PdO ones. CO pulse chemisorption and scanning transmission electron microscopy characterizations rule out the NO 2 effect on Pd size change. Powder X-ray diffraction and X-ray photoelectron spectroscopy characterizations were used to obtain palladium status of Pd/θ-Al 2 O 3 before and after reactions, indicating that in lean conditions at 650°C, the presence of NO 2 increases the content of active PdO on the catalyst surface, thus benefits methane oxidation. Homogeneous reaction between CH 4 , O 2 , and NO x may be partially responsible for the alleviation above 650°C. The interesting research of alleviation in transient deactivation by NO x , the components co-existing in exhausts, are of great significance for the application.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2016
·
IF 2.75
Yi Li,Muhammad Nadeem Amin,Xingmei Lu,Chunshan Li,Fuqiang Ren,Suojiang Zhang
The catalyst NiO/MgO–Al 2 O 3 was prepared by loading magnesium and nickel onto the surface of γ-Al 2 O 3 beads, respectively, and was adapted to in situ upgrade the high temperature pyrolysis vapor derived from coal pyrolysis. The catalyst synthesis process, and structural variation were characterized by the XRD, SEM, and physical adsorption analyzer. In order to examine the catalytic effect on the different nickel loading ratio in the catalysts, the solid–liquid–gas product distribution, variation of gas and components of coal tar were studied by simulated distillation, GC/MS, elemental analysis and so on. The results shows both the tar yield and the content of the light fraction in the tar can be increased by catalytic up grade. The catalyst has a strong ability to convert the heavy component and polycyclic aromatic hydrocarbons in the tar to lower molecular weight components.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of CO2 Utilization
·
2022
·
IF 8.321
Yutong Shen,Jun Xiao,Qijing Wu,Jingting Su,Li Zhu
To improve the conversion efficiency and reduce the CO 2 emissions associated with the reforming of biomass tar to syngas, photothermal catalysts were prepared in this study through various impregnation methods. Photothermocatalytic CO 2 reforming (PTCR) of benzene as a tar model compound, was conducted using the prepared Ni/TiO 2 -Al 2 O 3 catalysts. The results show that the introduction of TiO 2 facilitates the conversion of NiO to Ni during the photothermal reaction, while the photocatalysis of TiO 2 significantly enhances the photothermocatalytic activity of the Ni/Al 2 O 3 catalysts at low temperatures. Moreover, the methodology for catalyst preparation involving the loading of NiO before TiO 2 is also beneficial to catalyst performance. However, when the mass ratio of TiO 2 to Al 2 O 3 exceeds 1, the specific surface area, pore volume, and structural stability of the catalysts are reduced. The results of PTCR experiment show the following optimal Ni/TiO 2 -Al 2 O 3 catalyst preparation parameters: 25% NiO content and a TiO 2 /Al 2 O 3 ratio of 3:7; 450 °C calcination temperature and a nitrogen atmosphere. The maximum benzene conversion achieved through PTCR with the 0.25Ni/0.3Ti0.7Al(M2) catalyst is 88.2%. However, a large amount of coke is deposited onto the spent catalyst surface, contributing significantly to catalyst deactivation.
研究领域:
能源化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2023
·
IF 7.5
Xiaoyu Lin,Wenbin Ding,Gaojie Shi,Bochao Yan,Suping Zhang
Lignosulfonate (LS), as the most abundant technical lignin, is hard to depolymerize due to highly condensed structure. To overcome the limitation, in this work, NiMoO 4 /Al 2 O 3 catalyst with regulated acidity/hydrogenation activity was developed for highly efficient LS depolymerization . Results show that the performance of NiMoO 4 /Al 2 O 3 was improved by sulfur migration. Meanwhile Ni Mo alloy contributed to the good stability during LS depolymerization . The NiMoO 4 /Al 2 O 3 was favor for the intermediate compounds production by the cleavage of C O and C C bonds, which intermediate compounds were eventually hydrogenated to monomers by highly active MoS 2 . Also, NiMoO 4 /Al 2 O 3 and sulfonic groups play a synergistic role in the sulfur migration (only 39.1% bio-oil yield obtained by MoS 2 /Al 2 O 3 ). After reacting at 300 °C for 4 h, 81.7% of bio-oil yield with 95% desulfurization rate were obtained. Thus, it was demonstrated that an inexpensive catalyst was developed which can efficiently catalyze the depolymerization of lignosulfonate.
研究领域:
化学工程
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Wenjie Zhang,Jing Zhao,Linfeng Wang,Guofu Liu,Dekui Shen,Huiyan Zhang
The pyrolytic reforming of toluene to hydrogen and CNTs over the commercial and self-prepared Al 2 O 3 loaded with Fe through the impregnation method is investigated in a fixed bed reactor under the temperature from 600 °C to 800 °C. The physicochemical properties of Fe–Al 2 O 3 catalysts and Al 2 O 3 supports were characterized by XPS, H 2 -TPR, HRTEM and H 2 -pulse chemisorption . The reforming process over the catalyst of Fe loaded on self-prepared Al 2 O 3 gives the excellent H 2 yield of 27.8 mmol/(g-Fe) and graphite yield of 82.6 wt%, which is much higher than those from that over the catalyst of Fe loaded on the commercial Al 2 O 3 . It is evidenced by H 2 -pulse chemisorption that 5.1 % of Fe 0+ dispersion over the commercial Al 2 O 3 with mainly-exposed (110) facet while 11.2 % of Fe 0+ dispersion over self-prepared Al 2 O 3 with mainly-exposed (111) facet were obtained. The adsorption energy of iron cluster (Fe 4 ) with Al 2 O 3 (111) facet was estimated to be −14.5 eV through the DFT simulation, which is notably higher than that of iron cluster (Fe 4 ) with Al 2 O 3 (110) facet as −9.1 eV. With regard to the MD simulation along with XRD analysis of the Fe 3 C crystallite , Fe 0+ particles can be prominently molten at the high Fe 0+ dispersion over Al 2 O 3 facet, promoting the carbon solubility for the assembly of multi-wall CNTs without the deposition of unwanted amorphous carbon .
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
FUEL
·
2025
·
IF 7.5
Hong-Hui Gong,Xian-Yong Wei,Wen-Long Mo,Zhi-Min Zong,Guang-Hui Liu,Pei Liu,Kun-Peng Jiao
NiCs/Al 2 O 3 with medium-strong alkaline and the contents of Ni and Cs of 26.55 wt% and 0.02 wt%, respectively, was prepared by a three-step method and characterized with multiple tools. Oxydibenzene (ODB) and benzyloxybenzene (BOB) were used as low-rank coal-related model compounds and their catalytic hydroconversion (CHC) were investigated over NiCs/Al 2 O 3. Under mild conditions (MCs), NiCs/Al 2 O 3 can effectively activate H 2 to biatomic active hydrogen (H···H) and part of H···H can be effectively split to relative mobile H - and immobile H + on the NiCs/Al 2 O 3 surface. Both ODB and BOB can be completely converted and full hydrogenation (FH) of the benzene ring (BR) in −O-BR is the first step for the CHC of both ODB and BOB via H···H transfer to the BR under MCs. Subsequently, H - transfer to an ipso -carbon (IC) in the resulting oxydicyclohexane from the FH of ODB cleaves an −O-CH< bond to produce cyclohexane (CH I ) and cyclohexyloxy anion (CHOA), which abstracts H + from H···H to afford cyclohexanol (CH II ) followed by H - transfer to the IC in CH II and subsequent HO – release to yield CH I . As a result, CH I is the only final product from the CHC of ODB. In contrast, H - transfer preferentially proceeds to the carbon atom in the –CH 2 - of the resulting benzyloxycyclohexane from the FH of the BR in −O-BR of BOB to produce toluene and CHOA followed by the FH of toluene to get methylcyclohexane and the H + abstraction by CHOA from H···H to obtain CH II . Moreover, NiCs/Al 2 O 3 shows a distinguished recyclability and repeatability.
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
ENERGY & FUELS
·
2019
·
IF 3.021
Butian Xia,Liyuan Cao,Kaiwei Luo,Liang Zhao,Xiaoqin Wang,Jinsen Gao,Chunming Xu
The modified CoMo/γ-Al2O3 catalysts with different Ce and/or P loading were prepared by the incipient wetness impregnation method. The catalysts were characterized using X-ray fluorescence spectroscopy, N2-adsorption–desorption, pyridine Fourier transform infrared, H2 temperature-programmed reduction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The effect of Ce and/or P on the active phase, acidic properties, and catalytic activity of the CoMo/γ-Al2O3 catalysts were investigated in detail. The results showed that the phosphorus additive can slightly increase the stacking number of MoS2 slabs by reducing the metal–support interaction. Also, the addition of a small amount of cerium (1.75 wt %) not only increased the average slab length and stacking layer number of MoS2 slabs, but also formed new Brønsted acid sites on the support, which efficiently enhance the thiophene hydrodesulfurization (HDS) and olefins isomerization activity of the catalyst. These favorable effects are more obvious in cases where cerium and phosphorus coexist. The CoMo/γ-Al2O3P(2)Ce(1.75) catalyst exhibited the highest thiophene HDS and olefin isomerization conversion values of 98.58 and 19.51%, respectively. The high isomerization activity is able to inhibit the loss of gasoline octane number. Based on the above results, it can be concluded that the synergistic effect between Ce and P can achieve deep desulfurization and minimize the loss of octane number by modulating the acidity of the support and optimizing the active phase of the sulfided catalysts.
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
危险品化学品经营许可证（带存储）