ENVIRONMENTAL ENGINEERING SCIENCE
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2022
·Vol. 39
·期 1
·56-63
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IF 2.172
Jie Zhang,Ben Dong,Jing Liu,Wuxu Yang,Sijie Ge,Shilong He
In this article, Mn doping on Ce-based γ-Al2O3 (i.e., Mn-Ce-γ-Al2O3) was synthesized and then employed as catalysts to study the removal of phenol from aqueous solutions through catalytic ozonation process. The results showed that the phenol removal was remarkably increased to 97.50% if Mn-Ce-γ-Al2O3 was adopted as the catalyst. In addition, the kinetic rate of the reaction was increased, approximately, about 1.49 times when using Ce-γ-Al2O3 catalyst with Mn doping. Moreover, X-ray diffraction, transmission electron microscopy, Brunner-Emmet-Teller measurements, and X-ray photoelectron spectroscopy techniques were used to comprehensively characterize the physicochemical properties of the synthesized Mn-Ce-γ-Al2O3 catalyst, including the phases, morphologies, textural properties, and dispersity of the surface active species. More uniform channel mesoporous structures were obtained after Mn doping on Ce-γ-Al2O3, which could enhance the gas-liquid mass transfer rate, surface hydroxyl groups, Ce3+/Ce4+ ratio, and the formation of Mn-Ce solid solution. In this study, the effects of Mn doping on Ce-based γ-Al2O3 on phenol degradation were investigated and the removal mechanisms were suggested for a better understanding of the improved removal efficiency.
研究领域:
环境科学
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催化化学
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DOI
高影响因子
Journal of Energy Chemistry
·
2017
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IF 2.594
Jinwei Sun,Yujiang Wang,Haikui Zou,Xiaoguang Guo,Zhou-jun Wang
Nanosheet (S) and nanoplate (P) γ-Al 2 O 3 were synthesized by simple hydrothermal methods and employed as supports for Ni catalysts in CO 2 methanation . Both of the nanostructured Ni/Al 2 O 3 catalysts displayed good activity. In comparison, the Ni/Al 2 O 3 -S catalyst showed higher CO 2 conversion than the Ni/Al 2 O 3 -P counterpart at the reaction temperature ranging from 250 to 400 °C. The physical and chemical properties of the catalysts were systematically characterized by N 2 sorption , X-ray diffraction (XRD), high resolution-transmission electron microscopy (HR-TEM), hydrogen temperature-programmed reduction (H 2 -TPR) and CO 2 temperature-programmed desorption (CO 2 -TPD) techniques. Higher specific surface area and stronger metal-support interactions were confirmed on the Ni/Al 2 O 3 -S catalyst, which may lead to smaller particle size of Ni nanoparticles . Moreover, the Ni/Al 2 O 3 -S catalyst possessed more abundant weak and medium basic sites, which would benefit the activation of CO 2 . The smaller Ni size and more suitable basic sites may rationalize the superior activity of the Ni/Al 2 O 3 -S catalyst. Besides, the Ni/Al 2 O 3 -S catalyst exhibited excellent stability at 325 °C for 40 h.
研究领域:
化学工程
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催化材料
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2020
·
IF 3.573
Meng Chen,Wei Lu,Hejun Zhu,Leifeng Gong,Ziang Zhao,Yunjie Ding
Linear α-olefins (C8–C12 α-olefin, LAOs) are acknowledged as high-value-added chemicals in both lubricant production and the polyolefin industry. An alternative route to the synthesis of high-purity LAOs is the dehydration of linear long-chain n-alcohols, whereas elevating the activity and selectivity of catalysts remains a challenge. Herein, we presented that on using sodium-modified γ-Al2O3 as the catalyst, a high selectivity (up to 96.87%) to 1-decene was achieved, and an optimized experimental condition (329 °C and 0.25 h–1) was found using the response surface method. Characterization results including X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), pyrolysis (Py)-IR, NH3-temperature-programmed desorption (TPD), and CO2-TPD showed that a suitable ratio (∼0.4 wt %) of sodium impregnation could inhibit the strong acid sites of the catalyst, and sodium impregnation led to the formation of additional base sites, which accounted for the synergistic effect with other acid sites to promote further conversion of ethers to olefins. This work is of significance for the synthesis of LAOs from long-chain n-alcohols.
研究领域:
催化化学
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材料科学
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石油化工
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产品关联
DOI
高影响因子
ENERGY & FUELS
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2021
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IF 3.605
Beibei Feng,Yitong Zhai,Lidong Zhang
The combustion and catalytic combustion of ethanol (a typical bioalcohol) at atmospheric pressure and an equivalence ratio of ϕ = 3 were investigated in a flow reactor. Reactants, important intermediates, and products were detected and identified by gas chromatography–mass spectrometry. For ethanol combustion, the hydrogen abstraction reaction attacked by OH radicals is the initial pathway for ethanol consumption. Acetaldehyde is regarded as an important intermediate in ethanol combustion through kinetic analysis. However, catalytic combustion of ethanol over γ-Al2O3 is dominated by bimolecular and unimolecular dehydration reactions to produce diethyl ether and C2H4, while Pd/γ-Al2O3 can strongly oxidize ethanol to CO2 with a dramatic decrease in the decomposition temperature. To further understand the mechanism of catalytic combustion, pyrolysis and catalytic pyrolysis of ethanol were also explored. The product distribution in catalytic pyrolysis demonstrated weaker coke deposition over γ-Al2O3 in comparison to catalytic combustion. In addition, the deactivation of Pd/γ-Al2O3 at high temperatures was probably due to the increase in the concentration of oxygenated species to cover the active Pd site. The apparent activation energy was estimated by the Arrhenius equation to illustrate the difference in primary reaction channels. This work bridges the gap between combustion and catalytic combustion of ethanol, which is beneficial for the improvement of catalytic performance and control of pollutants by combining pyrolysis and combustion.
研究领域:
化学工程
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环境科学
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能源科学
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2021
·Vol. 28
·期 32
·43815-43830
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IF 4.223
Liu Yaxin,Ma Yongwen,Wan Jinquan,Wang Yan,Sun Jian,Xue Yangyang
In this work, Co-Ce-Zr/γ-Al 2 O3 3 particle electrodes were prepared for the efficient degradation of ciprofloxacin (CIP). Co-Ce-Zr/γ-Al 2 O 3 particle electrodes were analyzed with a scanning electron microscope (SEM), X-Ray Diffraction (XRD), X-Ray Fluorescence Spectrometer (XRF), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectroscopy (EDS). According to the results, significant amounts of Co 3 O 4 , CeO 2 , and ZrO 2 were formed on the Co-Ce-Zr/γ-Al 2 O 3 particle electrodes. It was shown that when the conditions of the reaction system were at pH=6, conductivity of 4 ms/cm, current of 0.2 A, initial pollutant concentration of 100 mg/L, and material dosage of 15 g, CIP could be completely degraded within 40 min, and the energy consumed in the reaction was 41.3 kWh/kg CIP. The rate of total organic carbon (TOC) removal by Co-Ce-Zr/γ-Al 2 O 3 particle electrodes was recorded to be approximately 52.6%. Using a response surface methodology, we explored the optimal operating conditions. At the same time, we also explored the influence of inorganic anions in water and actual water medium on the rate of CIP removal. In addition, the ESR data proved that the main active substance in the reaction system was ·OH. The degradation intermediates were investigated, and the possible mechanism was proposed. Thus, this research provided a new solution for the treatment of antibiotic-containing wastewater.
研究领域:
环境科学
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电化学
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废水处理
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产品关联
DOI
PubMed
高影响因子
CATALYSIS COMMUNICATIONS
·
2019
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IF 3.674
Cuncun Zuo,Yun Tian,Yanxia Zheng,Lei Wang,Zhongjun Fu,Tiantian Jiao,Ming Wang,Haofei Huang,Yuchao Li
Series of gold and ceria supported γ-Al 2 O 3 catalysts were developed for the oxidative esterification of methacrolein with methanol. All the catalysts were prepared through one step deposition-precipitation method, and K 2 CO 3 and urea were used as precipitant, respectively. Au, CeO 2 and γ-Al 2 O 3 could self-assemble unique particle morphology during co-precipitation process and form semi-core shell or core shell structure after calcination . The relationship between catalytic reactivity and structural characteristics were analyzed by SEM, TEM, EDS, BET, XRD, XPS, etc. Among Au-CeO 2 /γ-Al 2 O 3 (K 2 CO 3 ), Au-Ce/γ-Al 2 O 3 (Urea) and Au/γ-Al 2 O 3 (Urea) catalysts with different active components and precipitant, the last two exhibited higher catalytic activity. Moreover, the Ce-doped catalysts shown higher stability than just Au supported on pure alumina. The active stability of the optimum Au-Ce/γ-Al 2 O 3 catalyst was evaluated with seven-time cyclic reactions exhibiting high stability and activity with the yield of MMA above 90%.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Water Process Engineering
·
2025
·
IF 6.7
Liping Zhang,Huitong Li,Mengnan Duan,Weiwei Wang,Ran Mu,Zehua Pi,Yubin Shang
Coking reverse osmosis concentrates (ROCs) are characterized by a high organic content, complex composition, and difficulty in biological degradation. To achieve the zero liquid discharge (ZLD) strategy, ROCs need to be treated urgently. This work aims to prepare a modified catalyst under high-efficiency activated alumina (γ-Al 2 O 3 ) loaded with Fe and Co bimetals and to degrade m-cresol as a typical pollutant in actual coking ROCs. The results showed that Fe and Co metals were successfully loaded. Meanwhile, the catalyst enhances the reactive active sites, reduces the activation energy of the reaction, and improves the degradation efficiency. The degradation mechanism and removal process were investigated. The results showed that with the optimal conditions, as ozone dosage of 50 mg/L, gas flow rate of 400 mL/min, catalyst dosage of 30 g/L, and pH value of 9, the removal rates of COD, TOC, and UV 254 were 75.61 %, 56.22 %, and 84.14 %, respectively. This study provides a better treatment option for the degradation of m-cresols in coking ROCs.
研究领域:
环境科学
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催化化学
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产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
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2014
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IF 3.679
Yuming Cui,Na Liu,Yifen Xia,Jiangang Lv,Sujuan Zheng,Nianhua Xue,Luming Peng,Xuefeng Guo,Weiping Ding
1-Butene, abundant but inexpensive in industry, can be used to produce more valuable propene and ethene through the well-known metathesis reaction. In terms of catalyst system of molybdena, controlling the interaction between the molybdena and the support is quite crucial. A special support, i.e., well-shaped one-dimensional γ-Al 2 O 3 with uniform diameters of ∼10 nm and lengths of ∼100 nm, has been synthesized via oleylamine-assisted hydrothermal method. The molybdenum oxides are well controlled in sizes of moderate aggregation suitable for 1-butene metathesis with a fairly high rate of propene production (38.9 × 10 −9 mol m −2 s −1 , 30 mol% yield in a single pass) under mild conditions. The status of MoO x species in the catalyst has been investigated by solid state 29 Si MAS NMR, Raman, UV–vis, H 2 -TPR and NH 3 -TPD techniques. The catalyst, highly stable after twelve times of regeneration, is important for practical utilization for the metathesis reactions.
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2022
·Vol. 29
·期 53
·80399-80410
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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
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE BRAZILIAN CHEMICAL SOCIETY
·
2019
·Vol. 30
·期 2
·359-370
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IF 1.335
Zheng Zhi,Lei Tong,Wang Jun,Wei Yi,Liu Xuejun,Yu Fengwen,Ji Jianbing
In this paper, we report the catalytic cracking of soybean oil for biofuel over γ-Al2O3/CaO composite catalysts. The influence of catalysts, cracking temperature and weight hourly space velocity (WHSV) on the products distribution were investigated. The maximum yield (70.0 wt.%) of biofuel with low acid value (6.7 mg KOH g-1) and oxygen content (5.6%), as well as high calorific value (44.2 MJ kg-1) was achieved over 35 wt.% γ-Al2O3/CaO at 480 ºC and 3.72 h-1. The paper focused on the variation of biofuel composition and cracking pathway caused by γ-Al2O3/CaO composite catalysts via gas chromatography-mass spectrometry (GC-MS) and thermogravimetric (TG) analysis. Calcium oxide would react with fatty acid to yield calcium carboxylates at 300-350 ºC, which were subsequently decomposed into hydrocarbons (57.9 wt.%) and ketones (22.6 wt.%) at 415-510 ºC. As for 35 wt.% γ-Al2O3/CaO, the addition of γ-Al2O3 was beneficial to generate alkenes (38.2 wt.%), arenes (10.6 wt.%) and alcohols (12.3 wt.%) with ketones decreasing (16.5 wt.%) via γ-hydrogen transfer reaction and disproportination.
研究领域:
化学工程
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可再生能源
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催化材料
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2023
·
IF 3.8
Jianhui Su,Yan Liu,Xiujing Peng,Guoxin Sun,Xuchuan Jiang
Due to the high activation energy barrier and the sporadic nature of nucleation, the temperature required for the transition from cubic dense γ-Al 2 O 3 to tripartite α-Al 2 O 3 is as high as 1100–1200 °C. In this work, a two-step strategy was employed to reduce the phase transformation temperature, and prepare α-Al 2 O 3 particles with good dispersion. As the first step, 10 nm sheet γ-Al 2 O 3 was obtained by ammonium aluminum carbonate (AACH) decomposition, which was more favorable to the crystal transformation in the next ball-milling processing. In the second step, γ-Al 2 O 3 powder with partial α-Al 2 O 3 produced in situ by ball-milling γ-Al 2 O 3 was calcined, and α-Al 2 O 3 nanoparticles were obtained at just 850 °C. The content of the α-Al 2 O 3 is determined by the Rietveld Refine method. The relationship between ball-milling time and α-Al 2 O 3 content was clarified, and the effect of α-Al 2 O 3 content on the transformation temperature and morphology of γ-Al 2 O 3 was discussed. The results showed that the α-Al 2 O 3 content rises with the increase of ball milling time, and spherical α-Al 2 O 3 nanoparticles can be obtained when the α-Al 2 O 3 content is 5 %. The addition of α-Al 2 O 3 seeds reduces the phase transition temperature but agglomeration exists. Our proposed two-step low-temperature calcination strategy is an important method for the preparation of alumina nanoparticles
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2020
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IF 5.825
Lei Wang,Haiyan Liu,Yu Fan,Pei Yuan,Deqi Huang,S. Ted Oyama,Tinghai Wang,Xiaojun Bao
In alumina-based catalysts the properties of the alumina support directly influence the structure (size, morphology, orientation, etc.) of the resulting active phase and ultimately determine the performance of the final catalysts. This paper presents a facile and efficient method for γ-Al 2 O 3 to simultaneously expose {111} facets with strong acidity and {110} facets with moderate basicity. It is shown that the metal oxides NiO x and MoO x can be selectively deposited and subsequently sulfided on the respective facets to form a NiS 2 -MoS 2 /Al 2 O 3 catalyst with substantially enhanced activity for thio-etherification reaction. By cooperative action of the active sites on the newly exposed facets, the catalyst is shown to have superior activity over a conventional NiMoS/Al 2 O 3 catalyst in the thio-etherification reaction between ethanethiol and isoamylene (2-methyl-2-butene) to yield ethylamyl thioethers. Our findings show that tuning the physicochemical properties via crystal facet engineering and inducing cooperative catalysis via preferential deposition of active metals open a novel avenue for the rational design and synthesis of high performance catalysts.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
危险品化学品经营许可证（带存储）