Frontiers in Chemistry
·
2022
·
IF 5.545
Li Yongfeng,Liao Qianyan,Ling Weizhao,Ye Fan,Liu Fangfang,Zhang Xipeng,He Jiajun,Cheng Gao
Exploring high-efficiency and stable monolithic structured catalysts is vital for catalytic combustion of volatile organic compounds. Herein, we prepared a series of Pd/δ-MnO2 nanoflower arrays monolithic integrated catalysts (0.01–0.07 wt% theoretical Pd loading) via the hydrothermal growth of δ-MnO2 nanoflowers onto the honeycomb cordierite, which subsequently served as the carrier for loading the Pd nanoparticles (NPs) through the electroless plating route. Moreover, we characterized the resulting monolithic integrated catalysts in detail and evaluated their catalytic activities for toluene combustion, in comparison to the controlled samples including only Pd NPs loading and the δ-MnO2 nanoflower arrays. Amongst all the monolithic samples, the Pd/δ-MnO2 nanoflower arrays monolithic catalyst with 0.05 wt% theoretical Pd loading delivered the best catalytic performance, reaching 90% toluene conversion at 221°C at a gas hourly space velocity (GHSV) of 10,000 h−1. Moreover, this sample displayed superior catalytic activity for o-xylene combustion under a GHSV of 10,000 h−1. The monolithic sample with optimal catalytic activity also displayed excellent catalytic stability after 30 h constant reaction at 210 and 221°C.
研究领域:
环境科学
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催化材料
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2019
·Vol. 9
·期 8
·682
·
IF 3.444
Wenjie Sun,Xiaomin Li,Chao Sun,Zhen Huang,Hualong Xu,Wei Shen
Metal organic frameworks (MOFs) have recently been used as precursors of the catalysts for the combustion of volatile organic compounds (VOCs). In the present work, three kinds of CeO2catalysts were successfully synthesized from Ce-MOF-808, Ce-BTC, and Ce-UiO-66, with specific topological structures and coordinate environments. Catalysts with small particle size, stacking mode, and structural defects could be created by pyrolysis of Ce-MOFs, which affects the activity in the toluene combustion significantly. Raman spectra, XPS, and OSC studies were performed to reveal the formation of defect sites. The thermal redox properties were determined by H2-TPR. Catalytic activity tests were conducted on the toluene combustion, and CeO2-MOF-808 showed the best catalytic performance (T90 = 278 °C) due to its having the largest specific surface area, abundant active surface oxygen species, and low-temperature reducibility.Keywords:Ce-MOF;cerium oxide;catalytic combustion of toluene;environmental catalysis;pyrolysis process
研究领域:
材料科学
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环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Chunsheng Wan,Xiaofeng Wei,Guohui Cai,Dalin Li,Yingying Zhan,Yihong Xiao,Lilong Jiang
Al-doped Co 3 O 4 and CoO are prepared from Co‒Al hydrotalcite by calcination in air and N 2 atmospheres, and characterized by TG-DTA, XRD, SEM, N 2 adsorption, Raman, XPS, and H 2 -TPR. Co‒Al hydrotalcite is oxidized to Co(Co,Al) 2 O 4 in air accompanying with the collapse of layered structure, while in N 2 it decomposes to Co(Al)O that remains the plate morphology of hydrotalcite. In both cases, Al 3+ is doped into the lattice of cobalt oxides, leading to marked changes in the crystal size, surface state, and reducibility. Especially, Al-doped CoO shows smaller crystal size (4.1 nm), larger surface area (172 m 2 g ‒1 ), and higher degree of structural disorder than Al-doped Co 3 O 4 . Meanwhile, the Al-doped cobalt oxides show different reducibilities to those of Co 3 O 4 and CoO, indicating a strong interaction between cobalt and aluminum. The N 2 -calcined sample exhibits higher activity for benzene combustion than the air-calcined sample as well as a relatively good stability during heating/cooling cycles and a good long-time durability. Under the reaction atmosphere, Co(Al)O is transferred to Co(Co,Al) 2 O 4 . The resulting Co(Co,Al) 2 O 4 remains the original plate morphology and textural property and presents abundant surface adsorbed oxygen species, which accounts for its high activity.
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
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Decun Luo,Ziyu Tang,Xiyang Yu,Tao Zhang,Chun-Ran Chang,Zhun Hu
The effect of ZrO 2 crystalline phases on Pd/ZrO 2 for catalytic combustion of toluene was investigated. It was found that Pd/t-ZrO 2 showed superior activity when the toluene concentration was lower than 2000 ppm, while Pd/m-ZrO 2 performed better with toluene concentration higher than 3000 ppm. Kinetic studies showed that the reaction order of toluene on Pd/t-ZrO 2 and Pd/m-ZrO 2 is 0 and 2, respectively. The catalytic activity was controlled by combined effect of PdO activity and quantity, which was correlated with the interaction between palladium and zirconia. The t-ZrO 2 increased PdO species activity, while m-ZrO 2 could enhance the amount of PdO. DFT results showed that the p-band center of the O of PdO on t-ZrO 2 was higher, suggesting that PdO was more active. In situ -DRIFTS revealed that the reaction pathway of catalytic oxidation of toluene on Pd/ZrO 2 was as follows: toluene was oxidized stepwise to benzyl alcohol, benzaldehyde, benzoic acid , CO 2 and H 2 O.
研究领域:
催化化学
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环境科学
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材料科学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Yue Zhang,Cong Wu,Zhiqiang Wang,Jiawei Ji,Haiqin Wan,Weixin Zou,Qing Tong,Jingfang Sun,Lin Dong,Yu-Wen Chen
Herein, bimetallic Pt-Ir alloy nanoparticles (NPs) were successfully fabricated by ethylene glycol reduction of H 2 PtCl 6 ·6H 2 O and IrCl 3 through a microwave-assisted method. The Pt-Ir alloy NPs were deposited on CeO 2 catalysts for toluene combustion. The Pt 2.5 Ir/CeO 2 sample exhibited better catalytic activity at low reaction temperature, compared with monometallic catalysts. The excellent low-temperature catalytic activity was resulted from the interaction between Pt and Ir, richer adsorbed oxygen species and low-temperature reducibility. Furthermore, the in-situ DRIFTS was used to investigate the possible reaction pathway of Pt 2.5 Ir/CeO 2 . It showed that the broken of benzene ring on Pt 2.5 Ir/CeO 2 can be accomplished at lower temperature, resulting in enhancing the deep oxidation of toluene.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Mingshuo Tian,Zhiwei Huang,Jiangwei Ni,Wen Chen,Qiqi Zhou,Huazhen Shen,Xiaomin Wu,Huawang Zhao,Guohua Jing
The elucidation of active sites in Pt-based catalysts for benzene combustion has been a long-standing challenge, hindering the rational design of such catalysts. We have successfully pinpointed the active sites to the perimeters of Pt nanoparticles, deliberately excluding corner atoms. This achievement stems from a comprehensive approach, encompassing controlled synthesis of Pt nanocrystal size and morphology, advanced spectroscopic characterization, and detailed geometrical model analysis. We synthesized well-defined truncated hexahedral Pt nanoparticles with diameters (d) ranging from 2.2 to 6.6 nm. Notably, the turnover frequency (TOF) of our Pt/TiO 2 catalyst correlates inversely with the nanoparticle diameter, following a d -1.09±0.11 trend. This correlation matches the model-predicted perimeter-to-diameter ratio (excluding corners) with a d -1.01±0.09 exponent, confirming the location of the active sites. Further support comes from X-ray photoelectron spectroscopy and experiments using different support materials, which underscore the high activity at the Pt/TiO 2 interface. A crucial H 2 treatment step encapsulating the Pt nanoparticles by TiO x excludes both surface areas and corners as contributing active sites. The 0.7 % Pt/TiO 2 catalyst also demonstrated remarkable stability under testing conditions. In situ FTIR analysis provided insight into the stepwise mechanism of benzene combustion, revealing intermediate species and their transformation pathways. By finely tuning the geometry of Pt nanoparticles and correlating TOF with specific surface sites, our research highlights the perimeters of Pt atoms as the prime active sites for benzene combustion. These results contribute significantly to the field, offering a strategic approach to designing efficient catalysts for VOC elimination, with implications for both environmental protection and the advancement of catalytic science.
研究领域:
催化科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2023
·
IF 2.8
Wang Jing,Chen Hao,Jiao Chaonan,Dai Jian,Peng Yinxian,Ding Jian
The binary metal oxide-based catalysts have been proven to exhibit superior catalytic performances than their single metal oxides. As active supports, the physical and chemical properties of metal oxides would influence the chemical and electronic interactions with noble metal nanoparticles. By precise control of the composition and structure of metal oxides, the synergistic interaction between noble metals and transition metal oxides is expected to be realized. Herein, a novel hierarchical structured mCeO 2 NR/Mn 3 O 4 /Pt catalysts were designed for low-temperature toluene combustion. The mCeO 2 NR/Mn 3 O 4 composites were fabricated by a simple and effective two-step sequential hydrothermal synthesis approach. After subsequent loading of Pt nanoparticles over mCeO 2 NR/Mn 3 O 4 by impregnation and reduction methods, the mCeO 2 NR/Mn 3 O 4 /Pt catalysts with hierarchical structure were successively synthesized. The catalytical performances of the catalyst were evaluated by the toluene oxidation reaction. It was observed that the catalytic activities of the catalysts were closely related with the contents of Pt and Mn 3 O 4 , and mCeO 2 NR/Mn 3 O 4 /Pt with 2.1% Mn and 0.45% Pt exhibited the greatest catalytic activity ( T 95 = 165 °C) toward the oxidation of toluene. The apparent activation energy for toluene oxidation with mCeO 2 NR/Mn 3 O 4 /Pt (2.1% Mn) was as low as 35.3 kJ/mol. The improvement of the catalytical performance was due to the synergistic effect between CeO 2 and Mn 3 O 4 that led to the increase of oxygen vacancies and the enhancement of redox capacity, and the good dispersion of Pt active sites over the mCeO 2 NR/Mn 3 O 4 . Graphical Abstract
研究领域:
催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2018
·
IF 4.667
Yuexin Peng,Ling Zhang,Yiwen Jiang,Shichao Han,Qiuyan Zhu,Xiangju Meng,Feng-Shou Xiao
Catalytic combustion is considered as an efficient and economic technology to remove VOCs, and Al-ZSM-5 zeolite supported palladium catalysts (Pd/Al-ZSM-5) with good performances in this kind of reactions have been reported. In this work, it is found that Fe-ZSM-5 supported palladium catalyst (Pd/Fe-ZSM-5) exhibit higher catalytic activity in toluene combustion than the Pd/Al-ZSM-5, which is strongly related to more Pd 0 active species and higher concentration of absorbed oxygen species of Pd/Fe-ZSM-5 than those of Pd/Al-ZSM-5. More importantly, Pd/Fe-ZSM-5 has a good catalyst life and water-resistant ability, which should be potentially significant for practical applications in environment protection.
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 CATALYSIS
·
2022
·
IF 8.047
Jiancai Hou,Jiangliang Hu,Liping Chang,Jiancheng Wang,Zequan Zeng,Dongxia Wu,Xinmin Cui,Weiren Bao,Junxuan Yao
Cu-Ce mixed oxides with different Cu contents were synthesized through a sol–gel method, after which their effect on benzene combustion catalysis was evaluated. CeCu0.50 calcined at 300 °C (CeCu0.50–300) exhibited a high areal rate [2.0 × 10 −6 mol/(m 2 h)] and turnover frequency (0.16 s −1 ) at 170 °C, thus demonstrating the strong synergistic effect between CuO and CeO 2 . The catalyst durability and influence of H 2 O(g) on catalytic activity were also investigated. Correlation analyses between the catalytic activities and the amount of copper species, indicated that CuO x clusters and the Cu-[O x ]-Ce structure were the main active sites and bridge for oxygen transfer, respectively. Furthermore, benzene did not adsorb onto the copper species. The effect of temperatures on surface oxygen vacancies and oxygenated intermediates were also evaluated. Taken together, our findings provided key insights into the synergistic effects of different copper species on benzene combustion.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Ke-Xin Li,Yongfang Jin,Weimin Huang,Decun Luo,Tao Zhang,Xiaolong Han,Yuanhao Wang,Ralph T. Yang,Zhun Hu
CeO 2 with varied doping transition metal was investigated to understand the oxygen storage capacity and oxygen release property of CeO 2 -based catalysts for toluene combustion. The order of catalytic activity was as follows: CuCeO x ≈ CoCeO x > MnCeO x > FeCeO x > NiCeO x > ZrCeO x > CeO 2 . Kinetic studies showed that the reaction on CuCeO x proceed via an MvK mechanism and the oxygen of catalyst was crucial factor for the toluene combustion. H 2 -TPR and XPS showed the addition of transition metal to CeO 2 could modify the surface lattice oxygen. Moreover, the oxygen storage capacity and oxygen release properties showed the transition metal additive not only change the amount of oxygen, but also affect the oxygen mobility. A linear relationship was observed between the catalytic activity and oxygen storage capacity. Diffuse reflectance infrared fourier transform spectroscopy showed the toluene first adsorbed on the surface of catalyst, and then reacted with oxygen of catalyst to form benzyl, benzoate and benzyl carbonate species. All these results provided a new strategy to develop high performance catalyst.
研究领域:
催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2014
·Vol. 144
·期 11
·1851-1859
·
IF 2.291
Chen Chunyu,Wang Xiong,Zhang Jian,Pan Shuxiang,Bian Chaoqun,Wang Liang,Chen Fang,Meng Xiangju,Zheng Xiaoming,Gao Xionghou,Xiao Feng-Shou
Abstract A series of ZSM-5 zeolite with various cations (H + , Na + , K + , and Cs + ) and Si/Al ratios (60, 100, 300, and ∞) supported 0.5 % Pt have been prepared and tested in the combustion of toluene. It is found that Pt/KZSM-5-100 catalyst exhibits excellently high catalytic activity, negligible inhibition effect of H 2 O, and long catalyst life. Graphical Abstract 0.5 %Pt/KZSM-5-100 catalyst exhibits superior performance in combustion of VOCs, which would be potentially important for environmental protection.
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
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 27
·11557-11565
·
IF 3.288
Chao Miao,Junjie Liu,Jinxian Zhao,Yanhong Quan,Tao Li,Yongli Pei,Xiaoliang Li,Jun Ren
A rational approach for the optimization of cobalt based catalysts suitable for VOC combustion is to modulate the pore structure and increase the dispersion of active species. In this study, we have prepared CeO2–CoOx composite aerogels with a continuous porous structure using an epoxide-initiated gelation process and evaluated them in the catalytic combustion of toluene. The influence of the Ce/Co ratio on the structural properties and catalytic activities of the CeO2–CoOx aerogels was investigated using various characterization methods. The surface area of the CeO2–CoOx aerogels showed a volcanic curve versus the Ce content. A higher specific surface area of 172 m2 g−1 was observed for the CeO2–CoOx-10 catalyst with a Ce/Co ratio of 1/10. In addition, the presence of Ce modified the redox properties and the surface chemical states of the CeO2–CoOx aerogels, such as the surface Co3+/Co2+ ratios, and surface absorbed oxygen species (O− and O2−), which played key roles in their catalytic activity. In comparison with different cobalt-based catalysts for toluene oxidation in the previous literature studies, the CeO2–CoOx-10 catalyst in this work exhibited better catalytic performance, reaching an optimal toluene conversion of 90% at 248 °C as well as the highest stability during the durability test under different temperature stages.
研究领域:
材料科学
·
环境催化
·
化学工程
✓ 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）