APPLIED CATALYSIS A-GENERAL
·
2018
·
IF 4.521
Ting Yi,Yibo Zhang,Xiangguang Yang
Pt@CeO 2 /MCM-56 (PCM) and CeO 2 -CuO (9:1)/MCM-56 (CCM) were combined to purify the exhaust emissions from diesel vehicles in three configuration statuses, defined as configuration A—where CCM stays above PCM, configuration B—where PCM stays above CCM, and configuration C—where CCM mixes with PCM homogeneously in loose contact. Among these combined catalysts, the configuration A is most favorable for the selective catalytic reduction (SCR) reaction, with >80% NO x conversion obtained at the temperature range of 150–550 °C and gas hourly space velocity (GHSV) of 240,000 ml g −1 h −1 . NH 3 -TPD, H 2- TPR and NH 3 conversion measurements demonstrated that NH 3 can be selectively used to reduce NO x in the configuration A but is over-oxidized if the reaction is operated in configuration B or configuration C status, deteriorating the deNO x activity at temperature above 250 °C. Hence, configuration A not only takes advantage but also overcomes the shortcomings of PCM and CCM, leading to high NO x conversion and N 2 selectivity. A significant decrease in the onset temperature of soot combustion was also observed in this research.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 10
·2255
·
IF 4.2
Yan Cui,Zequan Zeng,Yaqin Hou,Shuang Ma,Wenzhong Shen,Zhanggen Huang
Noble metals have become a research hotspot for the oxidation of light alkanes due to their low ignition temperature and easy activation of C-H; however, sintering and a high price limit their industrial applications. The preparation of effective and low-noble-metal catalysts still presents profound challenges. Herein, we describe how a Ru@CoMn2O4spinel catalyst was synthesized via Ru in situ doping to promote the activity of propane oxidation. Ru@CoMn2O4exhibited much higher catalytic activity than CoMn2O4, achieving 90% propane conversion at 217 °C. H2-TPR, O2-TPD, and XPS were used to evaluate the catalyst adsorption/lattice oxygen activity and the adsorption and catalytic oxidation capacity of propane. It could be concluded that Ru promoted synergistic interactions between cobalt and manganese, leading to electron transfer from the highly electronegative Ru to Co2+and Mn3+. Compared with CoMn2O4, 0.1% Ru@CoMn2O4, with a higher quantity of lattice oxygen and oxygen mobility, possessed a stronger capability of reducibility, which was the main reason for the significant increase in the activity of Ru@CoMn2O4. In addition, intermediates of the reaction between adsorbed propane and lattice oxygen on the catalyst were monitored by in situ DRIFTS. This work highlights a new strategy for the design of a low-noble-metal catalyst for the efficient oxidation of propane.
研究领域:
催化
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化学工程
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysis Science & Technology
·
2022
·Vol. 12
·期 14
·4624-4636
·
IF 6.177
Yi Yang,Weixin Qian,Haitao Zhang,Zhonghao Han,Hongfang Ma,Qiwen Sun,Weiyong Ying
FeMnxZr and FeMnxZr2Na catalysts prepared by coprecipitation and impregnation methods were applied to investigate the promoting effects of Zr on iron-based catalysts for high-temperature Fischer–Tropsch synthesis (HTFT). Ar physisorption and TEM demonstrated that Zr-promoted catalysts have a larger BET surface area and larger pore volume, which are more conducive to the distribution of active phases. Zr promoted the dispersity of iron particles and reduced the grain size of iron particles, resulting in the improvement of the FTS activity. The CO-TPD and MES results revealed that the introduction of Zr promoted the dissociative adsorption of CO, thereby promoting the formation of the active phase χ-Fe5C2 while suppressing the formation of ε′-Fe2.2C and further improving the FTS activity and the selectivity to C2=–C4= in the hydrocarbon distribution. However, the addition of an excessive amount of Zr caused the excess ZrO2 to cover the surface of the active site, inhibiting the CO dissociative adsorption and the formation of χ-Fe5C2, resulting in a decrease in the CO conversion and the selectivity to C2=–C4=. The XPS and H2-TPR results proved the interaction between Fe2O3 and ZrO2. And the Fe–ZrO2 interaction inhibited the coke deposition and aggregation of the Fe species, as confirmed by XRD and TEM, respectively. The FeMn5Zr2Na catalyst exhibited the highest C2=–C4= selectivity of 34.4% at a CO conversion of 96.3%. And FeMn5Zr2Na displayed the highest production of light olefins (441.6 g h−1 kgCat−1), which was significantly higher than FeMn2Na (162.2 g h−1 kgCat−1).
研究领域:
催化
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化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
CATALYSIS LETTERS
·
2022
·Vol. 153
·期 3
·921-930
·
IF 2.936
Zhang Kai,Zhang Huanling,Feng Xipan,Wang Yue,Wang Guowei,Zhu Xiaolin,Li Chunyi
The catalytic activities of metal–based catalysts are largely dependent on the properties of their supports. The support (MgO, Al 2 O 3 , MgAl 2 O 4 , SiO 2, and CeO 2 ) effect of the Sn (1.2 wt%) based catalyst for the ethylbenzene dehydrogenation reaction was firstly investigated. The supported Sn-based catalysts were characterized by NH 3 -TPD, BET, XRD, and H 2 -TPR. Among the tested catalysts, the 1.2 Sn/CeO 2 catalyst presented the most effective catalytic activity, achieving a high ethylbenzene conversion of 56.2 wt% at 600 °C. The obvious support effect should originate from the electronic interaction between Sn and supports, instead of the geometric effect resulting from different dispersion of Sn species on carriers. The high activity of the 1.2 Sn/CeO 2 catalyst was attributed to the generation of oxygen vacancies on the CeO 2 surface. A typical strong metal-support interaction (SMSI) could be found in the 1.2 Sn/CeO 2 catalyst according to the comparison of H 2 -TPR, XPS, and Raman spectra result with pure CeO 2 support. The addition of Sn further promoted the generation of more oxygen vacancies by changing the redox properties of CeO 2 , and inhibited the agglomeration of CeO 2 nanoparticles, thereby enhancing greatly the catalyst's ethylbenzene dehydrogenation activity. Graphical Abstract
研究领域:
催化
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化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2021
·Vol. 12
·期 3
·737-749
·
IF 6.119
Zhicheng Xu,Yuran Li,Yuting Lin,Bin Wang,Panting Gao,Tingyu Zhu
The reduction of NO by CO was proposed to be applied for regeneration gas to remove NOx from industrial flue gas with activated carbon purification technology. To improve the activity and sulfur resistance for the reduction of NO by CO in regeneration gas, Cu and Fe modifications on activated carbon were investigated. And various samples were characterized by XRD, XPS, TPD, H2-TPR, in situ DRIFTS and DFT calculations to explain the reaction mechanism and poisoning mechanism. The synergistic effects of oxygen-containing functional groups and metal sites show that –COOH acts as an anchor site for metals and that C–O–C acts as a protective site for Fe3+ under a SO2 atmosphere. Cu2+ sites have a high activity at low temperatures due to the large amount of adsorbed NO and the intermediate NOx− participating in the reaction with the NOx− pathway. Fe3+ sites have a high activity at high temperatures due to the high N–O dissociation activity with the *N pathway and –NCO pathway. DFT calculations proved that the binding Cu2+ and Fe3+ sites have higher activity than free Cu2+ and Fe3+ sites. A high content of SO2 exhibits various poisoning effects, mainly including the sulfation of metal sites, deposition of S, and consumption of CO. AC-Fe-H exhibits excellent resistance and stability against SO2 and H2O due to less S deposition caused by consumption through the S–CO reaction, slight sulfation caused by the protective effect of Fe2+ and C–O–C on Fe3+ sites and better hydrophobicity.
研究领域:
环境科学
·
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Defu Yin,Renjie Ji,Jingyun Zhang,Shitao Yu,Lu Li,Shiwei Liu,Long Jiang,Ying Liu,Zhanqian Song,Yue Liu
A core–shell catalyst composed of mCeO 2 shell and Pd metal core was prepared by one-pot wet chemical method and used for the hydrogenation of phenol to cyclohexanone. The phenol conversion and cyclohexanone selectivity were 96.3 % and 95.3 % at reaction conditions of 50 min, 80 °C and 1 MPa H 2 . The effects of Ce species and Br species in the preparation of catalysts was studied, and the synthesis mechanism of core–shell Pd@mCeO 2 catalysts was preliminarily revealed. By discussing the phenol adsorption mechanism and the redox properties of the catalyst, the activation of H 2 by Pd sites and phenol by cerium oxide (CeO 2 ) sites of the surface were studied. H 2 -TPR and XPS characterization were used to explain the effect of Ce species and Br species for the catalytic performance. These results indicated that the electronic structure of Pd was regulated by the interaction between Pd and Ce, and different O sites were generated around the Pd sites. In situ IR spectra indicated that phenol was adsorbed and dissociated on cerium to form phenoxy species and water, this synergistic catalytic pattern of carrier activated substrate and hydrogenation site promoted the hydrogenation of phenol and improved the catalytic efficiency.
研究领域:
催化
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化学工程
·
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2022
·
IF 6.562
Zhuangqing Wang,Xinchao Wang,Chao Zhang,Yinze Yang,Leilei Zhou,Haiyang Cheng,Fengyu Zhao
Catalytic conversion of furfural and its derivatives to value-added C 5 molecules has attractive much attention in the field of biomass conversion . In this paper, the selective hydrogenolysis of tetrahydrofurfuryl alcohol to 1,5-pentanediol has been studied over a series of PrO x promoted Ni/Al 2 O 3 catalysts. The catalytic performances and the promoting effects of PrO x , as well as the role of Ni and PrO x species have been discussed. The surface properties and structure of catalysts were examined by TEM, XRD, XPS, H 2 -TPR, H 2 -TPD, in-situ DRIFTS, etc. The presence of PrO x species promotes the reaction rate and changes product selectivity significantly, and a 79.2% 1,5-pentanediol selectivity can be obtained at 88.4% conversion over the NiPr 1.2 /Al 2 O 3 catalyst. The synergistic effect between defect-rich PrO x and the adjacent active Ni species has been confirmed to contribute to the superior catalytic performances. These results provide useful knowledge for the activation of cyclic ether bonds and the design of heterogeneous catalysts with lanthanide oxide supports.
研究领域:
催化
·
生物质转化
·
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Qun Li,Tareque Odoom-Wubah,Yaping Zhou,Rafal Mulka,Yanmei Zheng,Jiale Huang,Daohua Sun,Qingbiao Li
The search for efficient and durable catalysts for volatile organic compounds oxidation is essential for environmental remediation. Herein, porous coral-like cobalt–manganese oxide (CoMnOx) catalyst was synthesized through annealing Co–Mn–1,3-propanediol precursors at 300 °C in air and applied for the catalytic oxidation of benzene. The as-prepared CoMnOx exhibited uniform porous coral-like structure, with an improved benzene catalytic abatement performance as compared to those of Mn3O4 and Co3O4 samples prepared by the same method, respectively. According to BET, H2-TPR, O2-TPD, and XPS analysis, the as-obtained CoMnOx catalyst showed the highest BET surface area, better low-reducibility temperature, and high content of absorbed oxygen groups when compared to Mn3O4 and Co3O4, which makes significant contribution to its catalytic benzene oxidation activity. Moreover, a plausible surface reaction mechanism for benzene oxidation over CoMnOx catalyst was also proposed through the in situ DRIFTS study.
研究领域:
环境科学
·
催化
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Yinghui Sun,Guojie Zhang,Jiwei Liu,Peiyu Zhao,Peng Hou,Ying Xu,Riguang Zhang
CH 4 CO 2 reforming to syngas was investigated over three different activated carbon catalysts. To better understand the influence of the supports on the catalytic properties , catalysts were analyzed by some characterization methods, such as nitrogen adsorption–desorption isotherms, XRD , H 2 -TPR, NH 3 -TPD, CO 2 -TPD, FTIR, TEM and EDX . The results showed that the catalyst with AC 2 as the support provided the best catalytic activity . The CH 4 conversion and CO 2 conversion were 92% and 98% at 900 °C, respectively; best selectivity with the H 2 /CO ratio was close to 1 among the three supports used. It also showed a better stability at 900 °C. H 2 -TPR analysis showed that Co species in Co/AC 2 catalyst were strong interaction with the support. It was observed that active metals were well dispersed on the AC 2 support by the TEM. In addition, the ratio of CH 4 /CO 2 also had great influence on the CH 4 and CO 2 conversion.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2018
·
IF 3.956
Qilei Yang,Ang Cao,Na Kang,Kang An,Zhao-Tie Liu,Yuan Liu
The catalyst for direct ethanol synthesis (DES) from syngas was investigated in this work, which is Co/La 2 O 3 -doped La 4 Ga 2 O 9 . The catalyst was prepared by using LaCo 1−x Ga x O 3 with perovskite phase as the precursor to intensify the interaction in the elements of Co, La and Ga. The catalysts were characterized by using XRD , H 2 -TPR, TEM , EDS, XPS , BET, ICP and TG techniques. This catalyst showed high selectivity to ethanol and excellent stability including excellent resistance to sintering and carbon deposition . It seems that the ethanol is generated in the interface between metallic Co and La 4 Ga 2 O 9 , and in the interface cobalt would be positively charged due to the interaction between Co nanoparticles and La 4 Ga 2 O 9 . The results and the related discussions indicate that Co/La 2 O 3 -doped La 4 Ga 2 O 9 catalyst is a promising catalyst for DES from syngas. Graphical abstracts.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2023
·Vol. 14
·期 1
·18
·
IF 3.9
Kaixuan Chen,Linsheng Xu,Yuanfeng Li,Jing Xiong,Dawei Han,Yaxiao Ma,Peng Zhang,Haoqi Guo,Yuechang Wei
Herein, we present an in-depth investigation into the enhancement of catalytic soot oxidation through cerium-doped three-dimensional ordered macroporous (3DOM) La-Co-Ni-based perovskites synthesized with the colloidal crystal template (CCT) method. The 3DOM structure significantly contributes to the accessibility and interaction efficiency between soot and catalyst. Based on the results of powder X-ray diffraction (XRD), N2adsorption-desorption measurements, scanning electron microscopy (SEM), temperature-programmed oxidation of NO (NO-TPO), temperature-programmed reduction of H2(H2-TPR), in situ infrared Fourier transform spectroscopy (In-situ DRIFTS), and temperature-programmed oxidation (TPO) reactions, the role of cerium doping in modifying the structural and catalytic properties of 3DOM perovskite-type La2−xCexCoNiO6catalysts was investigated systematically. The optimized cerium doping ratio in La2−xCexCoNiO6catalysts can improve the microenvironment for efficient soot-catalyst contact, enhancing the catalytic activity of soot oxidation. Among the catalysts, the 3DOM La0.8Ce1.2CoNiO6catalyst shows the highest catalytic activity for soot oxidation, whose T10, T50, and T90values are 306 °C, 356 °C, and 402 °C, respectively. The mechanism of the cerium doping effect for boosting soot oxidation is proposed: The doping of Ce ions can increase the surface oxygen species, which is the main active species for promoting the key step of NO oxidation to NO2in catalyzing soot oxidation. This research provides a new strategy to develop high-efficient non-noble metal catalysts for soot oxidation in pollution control and sustainable environmental practices.
研究领域:
催化
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PAPERS
·
2024
·Vol. 78
·期 4
·2275-2285
·
IF 2.1
Shu Ronglu,Du Yifan,Cao Liping,Zhao Hui,Luo Xiaoying,Wang Wei
Cerium samarium oxides catalysts with K + doping on the wall surface of cordierite honeycomb ceramics were preparation by sol–gel and dipping processes. Scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and Fourier transform-infrared spectroscopy were used to characterize the structural morphology and phase compositions. Through XPS analysis and H 2 -TPR measurement of monolithic catalyst, it is found that potassium ions improve the oxygen mobility in CeO 2 lattice and form surface active oxygen, increase the amount of oxygen adsorbed on the surface and improve the oxidation–reduction capacity. The catalytic combustion research demonstrates that T 10 , T 50 and T m in samples (Ce/Sm-0 K, Ce/Sm-0.3 K, Ce/Sm-0.5 K and Ce/Sm-0.7 K) decrease significantly compared with the blank reference (Cordierite). And the optimized sample Ce/Sm-0.5 K possess the lowest T 10 (389.6 °C), the lowest T 50 (425.5 °C), and the lowest T m (419 °C) in comparison with other samples. The cycle stability investigation reveals that sample Ce/Sm-0.5 K has excellent structural stability and stable catalytic performance, which has potential application in soot catalytic combustion field.
研究领域:
催化化学
·
材料科学
·
环境工程
·
化学工程
·
表面科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）