APPLIED CATALYSIS A-GENERAL
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2021
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IF 5.706
Huansheng Tan,Shibo Ma,Xiaoyu Zhao,Yushi Li,Chen Zhao,Yujun Zhu
Bimetallic W a CeO x (a = 0.06, 0.12, 0.18, 0.24) catalysts were synthesized for selective catalytic reduction of NO x with NH 3 (NH 3 -SCR). The influences of W on structure, activity and surface properties were investigated by XRF, XRD, Raman, TEM, N 2 adsorption-desorption, H 2 -TPR, O 2 /NH 3 /SO 2 -TPD, XPS, and in-situ DRIFTS. The characterization results show that the W/Ce ratio has a great effect on the NH 3 -SCR activity. The different catalytic activities of W a CeO x are mainly attributed to the acidity change, especially the increase of B-acid content plays a major role in enhancing low temperature activity. W 0.18 CeO x exhibits excellent low-temperature NH 3 -SCR activity, SO 2 /H 2 O resistance and N 2 selectivity with a broad activity window (190–490 °C) with 5%H 2 O. Moreover, good activity window (235–460 °C) can be maintained even the catalyst treated with 5% H 2 O at 800 °C for 12 h, showing especial hydrothermal stability. Thus, it can be summarized that W 0.18 CeO x is regarded as outstanding catalyst for low-temperature NH 3 -SCR of NO.
研究领域:
催化化学
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环境科学
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产品关联
DOI
高影响因子
Catalysis Science & Technology
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2020
·Vol. 10
·期 23
·8086-8093
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IF 5.721
Haoxi Jiang,Debin Kong,Ying Niu,Sheng Wang
MnO2–CoOX catalysts with different Mn/Co ratios were prepared using polyvinyl pyrrolidone (PVP) as an assistant to control the morphology and exposed crystal faces of composite oxides. The physicochemical properties of the catalysts were systematically characterized and the catalytic activity of NH3-SCR and resistance to SO2/H2O were investigated. It was found that the NO conversion over Mn–Co-0.2-PVP was apparently higher compared with that over Mn–Co-X-PVP (X = 0.9, 0.8, 0.6, and 0.4). This can be interpreted in terms of exposed crystal surface (110) and enhanced adsorption of NH3/NO, and better redox performance resulting from higher Co3+/Co2+ ratio. Furthermore, different PVP and HAc additives have different H2O and SO2 resistance. Mn–Co-0.2-PVP showed good resistance to H2O and SO2 poisoning owing to having more low-temperature (∼200 °C) NO adsorption sites, which are beneficial to promote the de-NOX reaction and less affected by SO2.
研究领域:
环境科学
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催化材料
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Xiangsen Xu,Jiangxiao Qiao,Shibo Yu,Jiahao Chen,Yiqing Zeng,Feng Zhang,Zhaoxiang Zhong,Weihong Xing
The rational design of catalysts and the establishment of uniform filter structure are key points in the development of high-performance catalytic filters. To resolve the issue of increased N 2 O concentration in catalysts with high vanadium content at high temperatures, a range of catalytic filters with low vanadium loading were fabricated by partially substituting vanadium in 6VWTi catalysts with transition metals (Mn, Cu, Co and Ce). The experimental results show that the introduction of Ce, which leads to rich surface-adsorbed reactive oxygen species, good redox properties and appropriate surface acidity, thus the 1V5CeWTi/SiC catalytic filter exhibits the highest denitration efficiency (NO conversion ＞90 % at the temperature of 300–500 °C without N 2 O production), presenting significant advantages in contrast to 1VWTi/SiC and 6VWTi/SiC. Furthermore, the preparation technology was optimized to obtain a more uniform structure, which enhanced NH 3 -SCR performance and reduced filter pressure drop. The optimized 1V5CeWTi/SiC also exhibited exceptional resistance to SO 2 + H 2 O and long-term stability for a duration of 200 h at 300 °C, as well as displays a noteworthy efficiency in filtering particulate matter (10 μm SiO 2 ). Therefore, the optimized 1V5CeWTi/SiC catalytic filter holds great potential in the realm of gas purification.
研究领域:
环境工程
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催化
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材料科学
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DOI
高影响因子
Molecular Catalysis
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2017
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IF 0
Peng Sun,Rui-tang Guo,Shu-ming Liu,Shu-xian Wang,Wei-guo Pan,Ming-yuan Li,Shuai-wei Liu,Jian Liu,Xiao Sun
CeSmOx mixed oxide catalysts supported on TiO 2 prepared by coprecipitation method were used for selective catalytic reduction of NOx with NH 3 . The results showed that the addition of Sm could effectively enhance the low-temperature SCR activity and SO 2 /H 2 O resistance of Ce/TiO 2 catalyst, and the appropriate mole ratio of Sm to Ce was 0.3. Characterization results indicated that the introduction of Sm could promote the formation of Ce 3+ and chemisorbed oxygen species on catalyst surface, which was favorable to the generation of NO 2 . Moreover, the doping of Sm could also promote the adsorption of NH 3 and NOx species on Ce/TiO 2 catalyst. The results of in situ DRIFT study revealed that the NH 3 -SCR reaction over CeSm/TiO 2 -0.3 catalyst was mainly controlled by the Langmuir−Hinshelwood mechanism in the low temperature range (<200 °C). Thereafter, the promoted NO oxidation and the enhanced NH 3 adsorption should play a major role for the excellent low-temperature SCR performance of CeSm/TiO 2 -0.3 catalyst.
研究领域:
催化
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环境科学
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材料科学
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DOI
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