Molecular Catalysis
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2024
·
IF 3.9
Wen-Xia Zhang,Xi Zhao,Lin-Ya Xu,Shuang Xia,Yu-Fen Zhou,Chong-Lai Chen,Hai-Hua He,Meng-Fei Luo,Jian Chen
The surface Pt species and adsorbed oxygen on the Pt/ZrO 2 catalyst were successfully modulated by altering the preparation methods, resulting in distinct catalytic behaviors for CO, n-heptane, and toluene oxidation. The Pt/ZrO 2 catalyst was initially prepared via wetness impregnation and subsequently reduced in an H 2 atmosphere to obtain the Pt/ZrO 2 -R catalyst. In contrast, the Pt/ZrO 2 -E catalyst was synthesized using ethanol solvent (also serving as a reducing agent) instead of water during wetness impregnation. Moreover, the pre-prepared Pt nanoparticles were loaded onto the ZrO 2 surface using polyvinylpyrrolidine (as a protective and structure directing agent) dissolved in ethanol solvent to fabricate the Pt/ZrO 2 -EP catalyst. Among these catalysts, the Pt/ZrO 2 -R exhibits superior catalytic activity towards CO oxidation due to its abundant metallic Pt species. It is found that activity of Pt/ZrO 2 catalyst for n-heptane oxidation is positively correlated with its surface adsorbed oxygen concentration, thus the highest activity is achieved over the Pt/ZrO 2 -EP catalyst possessing a higher concentration of surface adsorbed oxygen species. Unlike CO and n-heptane oxidation, toluene oxidation activity is affected by multiple factors, it is primarily promoted by synergistic catalysis between metallic Pt species (Pt 0 ) and surface adsorbed oxygen species over the Pt/ZrO 2 -EP catalyst. Our preliminary findings underscore that precise modulation of sensitive active sites on surfaces plays a critical role in specific catalytic reactions.
研究领域:
催化化学
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材料科学
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环境科学
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产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2018
·
IF 4.667
Ruimei Fang,Qiuyu Feng,Haibao Huang,Jian Ji,Miao He,Yujie Zhan,Biyuan Liu,Dennis Y.C. Leung
δ -MnO 2 was prepared via a facile in-situ redox reaction and used for catalytic oxidation of HCHO, a major indoor air pollutant. The washing treatment during catalyst preparation could impose great effect on content of K + and catalytic activity. δ -MnO 2 catalyst without washing treatment contains the highest content of K + ion and exhibits the best catalytic activity among various δ -MnO 2 samples. The HCHO removal efficiency keeps at 100% for first 600 min. The δ -MnO 2 samples were characterized by advanced technologies including XRD, Raman, XPS, TPR, TPD and in-situ DRIFTS. The XPS results indicates that K + ions increases the AOS value of Mn and the ratio of surface-adsorbed oxygen over δ -MnO 2 . The content of K + ions improves the amount and redox ability of surface mobile oxygen species, enhancing catalytic oxidation of HCHO.
研究领域:
环境科学
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催化材料
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DOI
高影响因子
CATALYSIS LETTERS
·
2022
·Vol. 152
·期 12
·3843-3852
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IF 2.936
Huang Xuehui,Yang Na,Li Xiaobo,Pan Hongyun,Song Xiaozhan,Chang Yu
La 0.8 Sr 0.2 MnO 3 (LSM) catalyst has been successfully prepared by solid phase method (G-LSM-T), sol–gel method (C-LSM-T) and molten salt method (S-LSM-T), using as-prepared MnCO 3 microspheres as templates, respectively. It was shown that the S-LSM-550 catalyst presented well-formed perovskite structures, large specific surface area (49.65m 2 /g) and promising catalytic activity in CO oxidation, which T 50 and T 90 for CO conversion over fresh S-LSM-550 were 145.14 °C and 170.73 °C. The S-LSM-550 calcined at 550 °C for 2 h exhibited excellent thermal stability and catalytic activity compared with the samples prepared by solid phase method and sol–gel method. Its superior catalytic performance could be greatly attributed to its stable microstructure, high surface Mn 4+ /Mn 3+ molar ratio and more available surface adsorbed oxygen species. Graphical Abstract
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2017
·
IF 4.636
Yuexin Peng,Ling Zhang,Long Chen,Dingzhong Yuan,Guoxiong Wang,Xiangju Meng,Feng-Shou Xiao
Catalytic combustion of toluene has been widely investigated due to importance of abatement of volatile organic compounds (VOCs), and in this work we have successfully prepared highly efficient heterogeneous catalysts for toluene combustion by impregnation of manganese oxides with Al-rich Beta zeolites (Beta-SDS) with H-form (MnO x /H-Beta-SDS) and K-form (MnO x /K-Beta-SDS) as well as pure siliceous Beta zeolite (MnO x /Si-Beta). Catalytic tests show that these zeolite-supported catalysts have higher activities than alumina-supported manganese oxides (MnO x /Al 2 O 3 ). By comprehensive consideration of reducibility, adsorbed oxygen species, and lattice oxygen species in the catalysts, it is shown that the adsorbed oxygen species play more important roles than others for the catalytic activity. The good catalytic performance and understanding of active sites over the MnOx/H-Beta-SDS might be helpful for preparation of catalysts in VOCs abatement.
研究领域:
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
JOURNAL OF ALLOYS AND COMPOUNDS
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2024
·
IF 5.8
Qihua Liang,Guotao Lin,Junting Gao,Zequan Li,Qingge Feng
Formaldehyde is a ubiquitous indoor pollutant. Developing metal oxide semiconductors gas sensors for selective ppb-level formaldehyde detection is challenging. Therefore, developing gas sensors that can selectively detect indoor formaldehyde at ppb levels is important. In this study, outer-walled thin sheet-like microspheres of Ga-doped In 2 O 3 (Ga x In 2-x O 3 , x = 0, 0.1, 0.2, 0.3, and 0.4) were fabricated using a facile two-step synthetic method. The Ga 0.3 In 1.7 O 3 based sensor shows the response (556 ± 25) to 100 ppm formaldehyde at 80 °C, which is around 6.5 times that of the pure In 2 O 3 based sensor at 90 °C. Furthermore, it has fast response time (< 3 s), excellent selectivity (S Formaldehyde /S Ethanol = 160, S Formaldehyde /S Acetone = 267), good stability (at least 60 days), and ultra-low limit of detection (10 ppb) for formaldehyde at 80 °C. The improved formaldehyde sensing performance of Ga 0.3 In 1.7 O 3 microspheres is attributed to the optimization of surface chemisorbed oxygen, which is caused by Ga doping regulating the Fermi level of In 2 O 3 as well as an increase in the specific surface area.
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
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
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催化科学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2016
·Vol. 6
·期 14
·5580-5589
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IF 5.287
Zijian Feng,Jianqiang Wang,Xiao Liu,Yanwei Wen,Rong Chen,Hongfeng Yin,Meiqing Shen,Bin Shan
A series of LaxSm1−xMn2Oδ (x = 0, 0.1, 0.3, 0.5) catalysts were synthesized through a co-precipitation method. The catalytic activity for NO oxidation was enhanced with La substitution, and the maximum activity was achieved at x = 0.3. XRD and HRTEM results revealed the formation of a multiphase oxide as well as the interface structure between the mullite (SmMn2O5) phase and Mn-rich perovskite (La0.96MnO3.05) phase. The main impact of different La/Sm molar ratios is the amount of surface adsorbed oxygen (Oads) and surface Mn4+ ions as revealed by XPS results. The NO oxidation performance was enhanced through La addition by promoting the decomposition of nitrate/nitrite species and desorption of NO2, improving the reducibility of surface adsorbed oxygen, as determined by H2-TPR, NO + O2-TPRD and in situ DRIFTS studies. Mono-, bi-dentate and bridged nitrates formed on the surface were determined to be the primary reaction intermediates.
研究领域:
催化化学
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材料科学
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环境化学
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表面科学
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无机化学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2021
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IF 7.312
Jiayu Feng,Fei Wang,Chi Wang,Kai Li,Ping Ning,Xin Sun,Lijuan Jia
A series Ce m Cu n O x /HZSM-5 sorbents were introduced to remove PH 3 in low-temperature and low-oxygen environments. The effects of copper loading and cerium doping on the adsorption–oxidation performance of the sorbents were investigated. Experimental results showed that doping with 1 wt% of cerium (Ce 1 Cu 30 O X /HZSM-5) could significantly improve the performance of the sorbent. The PH 3 breakthrough capacity was identified as 114.36 mg(PH 3 )•g sorbent -1 . In addition, after three thermal regeneration cycles, the sorbent still has ideal performance. X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS) analyses exhibited that CuO was the main active species, and Ce-doping can increase the chemisorption oxygen on the surface of the sorbent. BET results demonstrated that the introduction of cerium could improve the specific surface area and pore volume of sorbent. Hydrogen temperature-programmed reduction (H 2 -TPR) and scanning electron microscope (SEM-EDS) indicated that cerium species played an important role in uniformly dispersing copper species on the HZSM-5 surface and improving the oxidation performance of sorbent. Moreover, the reaction products and mechanisms were also investigated by XRD, XPS, and in-situ FTIR spectra. The results indicated that the consumption of CuO and the accumulation of phosphorus species (e.g., P, P 2 O 5 , and Cu 3 P) on the surface and inner pores of the sorbent were the primary reasons for the deactivation of the sorbent.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2016
·
IF 4.012
Peng Sun,Rui-tang Guo,Shu-ming Liu,Shu-xian Wang,Wei-guo Pan,Ming-yuan Li
A series of MnEuOx catalysts were prepared by the co-precipitation method and used for selective catalytic reduction of NOx with NH 3 . It was found that the modification of MnOx catalyst by Eu with a Eu/Mn molar ratio of 0.1 could greatly enhance its SCR activity and broaden its operating temperature window, accompanied by good resistance to SO 2 and H 2 O. From the characterization results of N 2 adsorption, XRD, XPS, H 2 -TPR, it could be concluded that the larger surface area resulted from the inhibited crystallization of MnOx, the enrichment of surface Mn 4+ and chemisorbed oxygen, and the higher reducibility all made a contribution to the high SCR activity of MnEuOx-0.1 catalyst. Furthermore, the results of in situ DRIFTS study revealed the NH 3 -SCR reactions over MnOx and MnEuOx-0.1 were mainly controlled by L-H mechanism (<150 °C) and E-R mechanism (>150 °C) respectively, and the contribution of E–R mechanism became more important with increasing reaction temperature. The enhanced NO oxidation and NH 3 adsorption should be mainly contribute to the distinguished SCR performance of MnEuOx catalyst in the lower temperature range (<150 °C) and higher temperature range (>150 °C) respectively.
研究领域:
催化化学
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环境科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xue Ma,Xin Dong,Baosheng Li,Qiuyue Zheng,Rui Li,Chaobo Huang,Lihua Huo,Xianfa Zhang,Xiaoli Cheng,Yingming Xu
n-Pentanol, a commonly used Volatile organic compounds (VOCs) in industry, is harmful to the environment security and human health. Thus, it is necessary to develop n-pentanol sensors. Herein, spherical (ZTO-S), cubic (ZTO-C) and pseudo-cubic (ZTO-PC) ZnSnO 3 were obtained by changing the ratio of solvent in hydrothermal/solvothermal process. By contrast, the ZTO-PC sensor had a high sensitivity of 135.2 to 100 ppm n-pentanol at 170 °C, a short response time of 0.8 s, and a low detection limit of 10 ppb. Meanwhile, the ZTO-PC sensor displayed superior reproducibility, good humidity resistance and excellent long-term stability. The outstanding sensing performance response of the ZTO-PC sensor is attribute to its high surface adsorbed oxygen content, fast electron mobility and good conductivity, providing abundant active sites and effective gas adsorption platform. In addition, the mechanism of the ZTO-PC sensor for n-pentanol was studied by XPS , GC-MS, and in-situ DRIFTS . After contact with ZnSnO 3 , n-pentanol was first oxidized to n-pentanal and then decomposed into CO 2 and H 2 O. This work well-designed three types of ZnSnO 3 through morphological engineering, providing a hopeful strategy for improving the gas sensitive performance.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
·
IF 16.744
Yanke Yu,Desheng Wei,Zhaojian Tong,Jinxiu Wang,Jinsheng Chen,Chi He
Ammonia (NH 3 ) is a critical component causing environmental problems like haze and water pollution. Selective catalytic oxidation of ammonia (NH 3 -SCO) to N 2 and H 2 O is a promising method to abate NH 3 emission. However, inferior SO 2 tolerance is still a tremendous challenge to be conquered for present NH 3 -SCO catalysts regarding practical applications. Application of materials which was difficult to be sulfated by SO 2 should be an effective way to solve this problem. Here, a ReO x -CuSO 4 /TiO 2 catalyst which coupled the advantages of ReO x (Rhenium oxides, supplying highly active adsorbed surface oxygen enhancing NH 3 -SCO reaction) and CuSO 4 (providing Brønsted acid sites inhibiting the formation of N 2 O) was rationally fabricated. Results indicated that ReO x -CuSO 4 /TiO 2 catalyst exhibited excellent catalytic performance in NH 3 -SCO with almost 100% of NH 3 oxidized at 300 °C (N 2 selectivity as high as 96%). Crucially, the composite catalyst exhibited incredible activity and stability under harsh reaction conditions toward SO 2 (600 ppm) and H 2 O (4.0 vol%) owing to the superior inhibition capability for SO 2 adsorption. In situ DRIFTS, in situ Raman and in situ XPS demonstrated that the NH 3 -SCO reaction over ReO x -CuSO 4 /TiO 2 catalyst mainly obeyed a N 2 H 4 reaction mechanism and oxidation–reduction circle between Re 7+ and Re 6+ played a vital role. Moreover, SO 2 would not affect this reaction mechanism on ReO x -CuSO 4 /TiO 2 catalyst. The knowledge and understanding reported could provide critical insights for the design and optimization of efficient materials for industrial NH 3 oxidative elimination.
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
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yeshuang Wang,Mingxian Duan,Zhelin Su,Chao Yang,Yuxiao Wang,Tian Kou,Jiawei Kou,Huiling Fan
Cu–1,3,5-benzenetricarboxylate (Cu–BTC) exhibited potential for hydrogen sulfide (H 2 S) removal, however, its sulfur capacity is limited due to it relies only on the adsorption reaction path. Herein, a series of Fe-doped Cu–BTC materials (denoted as x Fe–Cu–BTC) were synthesized to enhance H 2 S removal capacity via a adsorption–oxidation bifunctional synergism mechanism. The prepared materials were characterized using various techniques, and their H 2 S removal performance was measured under dry and ambient conditions. The experimental results demonstrated that the 18%Fe–Cu–BTC shown the optimal breakthrough sulfur capacity of 122.8 mg S/g, marking a 2.1-fold and 10.3-fold improvement over pure Cu–BTC and Fe–BTC, respectively. The characterization analyses revealed that the Cu 2+ active sites initially react with H 2 S to form CuS, while the incorporated Fe 3+ sites trigger the oxidation of CuS, yielding elemental sulfur, Cu 2+ and Fe 2+ . The resultant Cu 2+ and Fe 2+ further engage in reactions with H 2 S to form CuS and FeS, thereby enhancing the H 2 S removal capacity via dual reaction pathways of adsorption and oxidation. Additionally, appropriate Fe doping increased the specific surface area and pore volume of Cu–BTC, which exposed more active sites and improved molecular diffusion. Based on the obtained findings, a plausible desulfurization mechanism involving adsorption and oxidation synergism for remove H 2 S was proposed.
研究领域:
材料科学
·
环境科学
✓ 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）