Journal of Environmental Chemical Engineering
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2024
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IF 7.4
Yanli Zhang,Jian Li,Jianyu Cai,Shuangye Li,Xing Fan,Liyun Song,Ruixue Guo,Jiasheng Liu
In this study, a series of γ-Fe 2 O 3 -modified V 2 O 5 -MoO 3 /TiO 2 (VMT) catalysts was prepared by wet impregnation method. The γ-Fe 2 O 3 -modified catalysts exhibited excellent catalytic performance, and 1.25 wt% γ-Fe 2 O 3 content improved the deNO x efficiency at 150 °C from 54% (unmodified VMT catalyst) to 84% (modified catalyst). BET, XRD, XPS, NH 3 -TPD, H 2 -TPR, and in situ DRIFTs were employed to characterize the physicochemical properties and reaction mechanisms of the catalysts. The introduction of γ-Fe 2 O 3 increased the V 5+ /V 4+ ratio, surface chemisorbed oxygen content, redox ability, and a number of acid sites in the prepared catalysts. XPS confirmed the addition of γ-Fe 2 O 3 introduced new charge transfer pathways (Fe 3+ /Fe 2+ ↔ V 5+ /V 4+ ). In situ DRIFTs suggested that the addition of γ-Fe 2 O 3 to the catalyst significantly increased the adsorption capacity of catalyst for NH 3 and NO x , while also exerting a strong activating effect on the adsorbed NH 3 . Furthermore, selective catalytic reduction over the VMT and 5PEG@1.25Fe-VMT catalysts followed the Eley-Rideal (E-R) mechanism. At temperatures above 200 °C, the 5PEG@1.25Fe-VMT catalyst also followed the Langmuir-Hinshelwood (L-H) mechanism.
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 PHYSICS AND CHEMISTRY OF SOLIDS
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2021
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IF 3.995
Li Huang,Yiqing Zeng,Yibo Gao,Hu Wang,Yuhao Zong,Zhengfeng Chang,Shule Zhang,Pei Han,Yang Yu
The oxidation of SO 2 into SO 3 promote the formation of NH 4 HSO 4 (ABS), which can cover surface active sites catalyst, and then leading to the decrease of NH 3 -SCR De-NO x activity. In this work, phosphorus species were loaded on the V 2 O 5 -MoO 3 /TiO 2 De-NO x catalyst to enhance its SO 2 resistance via inhibiting the SO 2 /SO 3 conversion. XRD and N 2 -adsorption results showed that phosphorus has little impact on the structure and pore property of the catalyst. The results of XPS , H 2 -TPR, and NH 3 -TPD analyses illustrated that suitable amount of phosphorus (1%) increases the content of polymeric vanadate and chemisorbed oxygen (O α ) of the catalyst, which is benefit to the SCR process. Phosphorus species decreases the SO 2 absorbability and SO 2 oxidation activity of V-Mo-P/Ti catalysts, thus it exhibits higher NH 3 -SCR activity than that of the P-free catalyst at presence of SO 2 due to the lower SO 2 /SO 3 conversion and fewer amount of NH 4 HSO 4 deposition.
研究领域:
环境科学
·
催化化学
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DOI
高影响因子
Industrial Chemistry & Materials
·
2025
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IF 11.9
Yan-Chao Qu,Guangyue Xu,Chen Chen,Jianhua Guo,Dingjia Liu,Haiwei Jia,Haonan Guo,Shuya Jia,Jiazhen Jia,Ying Zhang,Lifeng Yan
The development of novel low-temperature selective catalytic reduction (SCR) denitrification catalysts is a crucial research direction for reducing pollution and carbon emissions. Although V2O5-MoO3/TiO2 catalysts have been widely used in commercial applications, achieving effective SCR denitrification for low-temperature flue gases remains a significant challenge. In this study, the catalytic efficiency of the catalysts was systematically investigated and optimized by constructing Pearson linear correlation coefficient models between catalytic activity and different pore structures, substrate crystal planes, and active site components and properties, etc. Through comprehensive characterizations and experiments, anatase TiO2 loaded with 3% V2O5 and 10% MoO3 was developed and demonstrated excellent catalytic activity and stability even in high sulfur content and low-temperature environments. The catalyst was deployed in a pilot plant for over two years, consistently achieving a monthly average denitrification efficiency of over 67% and maintaining an outlet NOx concentration below 50 mg/Nm³. This study provides a robust and efficient low-temperature catalyst for SCR denitrification and offers valuable insights for future catalyst optimization.
研究领域:
环境科学
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催化
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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
APPLIED SURFACE SCIENCE
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2020
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IF 6.182
Zulfiqar Ali,Yang-wen Wu,Yue Wu,Zulqarnain Arain,Ming-xin Xu,Qiang Lu,Heping Ma,Huan-yu Zhao
Lead (Pb) species are inescapable constituents of the flue gas from coal-fired power plants and other thermal devices, which can cause impeding effects on the selective catalytic reduction (SCR) reactions. Here, the poisoning effects of Pb on the V 2 O 5 -MoO 3 /TiO 2 type SCR catalyst were examined. The poisoned catalysts were prepared by the solid diffusion and incipient wetness impregnation (IWI) methods. The catalytic activity tests indicated that the Pb-doped catalyst prepared by the IWI method suffered a considerable drop in catalytic activity, while a slender influence was observed on the Pb-loaded catalysts prepared by solid diffusion method. Comprehensive characterizations and density functional theory (DFT) calculations were performed on the fresh and poisoned catalysts prepared by the IWI method to unveil the deactivation mechanism. The results showed that Pb species covered the active sites (V species) on the catalyst surface, resulted in the decrease in chemisorbed oxygen, hence reducing the surface acidities. The decrease in reducibility of the catalyst was an important factor for poisoning of the catalyst. Moreover, Pb species reacted with MoO 3 to form PbMoO 4 which agglomerated on the catalyst surface to further deactivate the catalyst.
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 HAZARDOUS MATERIALS
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2026
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IF 10.6
Xiaoqiang Wang,Wenjie Liao,Yongyong Cao,Yue Liu,Zhongbiao Wu
In this study, a series of V 2 O 5 -MoO 3 /TiO 2 (VMo/Ti) catalysts were prepared using TiO 2 supports with varying specific surface area for selective catalytic reduction of NO x by ammonia (NH 3 -SCR). The activity tests revealed that the NO conversion of different samples showed a volcano-type variation with surface area rising, where the VMo/Ti-S3 catalyst with moderate surface area possessed the best SCR activity (>80% NO conversion at 250 °C). Meanwhile, the SO 2 oxidation ratio decreased at an elevated surface area. At 350 °C, the SO 2 oxidation ratio of VMo/Ti-S1 catalyst with lowest surface area was about 4.4%, which was around 4 times that of VMo/Ti-S4 sample with highest surface area. Characterization results indicated that, as the surface area increased, both the redox capacity and surface acidity were enhanced. And the vanadium oxides became less polymeric with a gradual increased ratio in dimeric vanadium species and finally more monomer VO x formation, corresponding to the highest SCR activity of VMo/Ti-S3 catalyst. Additionally, the characterization results indicated that the chemisorption of SO 2 was inhibited on high-surface-area catalysts, which was consistent with DFT results. And DFT simulations also confirmed an increased energy barrier for SO 2 oxidation to generate SO 3 process on less polymeric vanadium species. Both the results above indicated the critical role of vanadium polymerization state in SCR activity and SO 2 oxidation. This work offers new insights into the development of efficient SCR catalysts with low SO 2 oxidation rates for industrial applications.
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DOI
PubMed
高影响因子
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