Article
Chemistry, Physical
Changsheng Qu, Shuang Lin, Danyang Zhao, Jiachen Zhu, Hao Zhou, Dongyao Xu
Summary: This study investigates the impact of metal doping on the DeNOx and anti-poisoning performance of MnOx/mZrO2. The results show that Sm doping has a more significant effect on both the DeNOx performance and anti-poisoning performance, while Co doping has a relatively minor impact on the DeNOx performance. This is because the interaction between Sm and Mn results in improved redox performance and the presence of more acidic sites, inhibiting the formation of sulfate and ammonium sulfate.
CATALYSIS COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Jinkun Guan, Lusha Zhou, Weiquan Li, Die Hu, Jie Wen, Bichun Huang
Summary: The Gd-modified MnOx/ZSM-5 catalysts showed excellent catalytic activity and SO2 resistance in low-temperature NH3-SCR reactions, attributed to their large surface area, abundant Mn4+ and surface oxygen species, strong reducibility, and suitable acidity. The addition of Gd inhibited the reaction between SO2 and MnOx active sites, leading to enhanced SO2 resistance. Furthermore, the mechanism of low-temperature SCR reactions over Mn/Z and GdMn/Z-0.3 was found to follow the Langmuir-Hinshelwood and Eley-Rideal mechanism, as revealed by in situ DRIFTS experiments.
Article
Chemistry, Physical
Xianlong Zhang, Shiwen Liu, Kang Ma, Yazhong Chen, Shi Jin, Xinyu Wang, Xueping Wu
Summary: Manganese oxide-supported palygorskite (MnOx/PG) catalysts are efficient for low-temperature SCR of NOx, but tend to be poisoned by SO2. The deactivation mechanism involves the formation of polysulfuric acid due to oxidation of SO2, leading to wrapping of the active component and blocking of micropores. Water-washed regeneration can recover the catalyst activity.
Article
Energy & Fuels
S. Raja, M. S. Alphin, L. Sivachandiran, Pratichi Singh, Devaiah Damma, Panagiotis G. Smirniotis
Summary: The addition of Cu and/or CNTs to the catalyst was found to be beneficial for improving its activity; a catalyst with 5% Cu loading exhibited the best performance; the addition of CNTs increased the specific surface area of the catalyst; Cu loading enhanced Mn4+ species and chemisorbed oxygen species on the catalyst surface.
Article
Chemistry, Inorganic & Nuclear
Hongli Wu, Weizao Liu, Ya Liang, Qingcai Liu
Summary: The incorporation of inert silica into pure MnOx effectively improved the resistance of Mn-based catalysts to lead toxicity and enhanced their activity in the selective catalytic reduction of NOx with ammonia (NH3-SCR). The presence of PbCl2 occupied the active Mn sites and resulted in a decline in the surface acidity and oxidation performance of the catalysts. However, silica played a crucial role in preserving the activity of Mn sites by preferentially bonding with PbCl2, generating more active intermediates. This work provides mechanistic insights into the role of SiO2 in regulating the surface acidity and stability of Mn-based catalysts, which is useful for designing catalysts with high Pb resistance for the NH3-SCR reaction.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Javier Ruiz-Martinez, Lieven E. Gevers, Linga R. Enakonda, Ameen Shahid, Fei Wen
Summary: This study investigates the poisoning effect of SO2 on binary MnTi and ternary MnCeTi mixed oxides for the NH3-SCR reaction. The addition of Ce widens the optimal operational temperature range, but the presence of SO2 drastically decreases catalytic activity in all catalyst samples. Further characterization reveals adsorption and poisoning of SO2 on the catalysts, and doping studies do not provide effective solutions to suppress SO2 deactivation.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
Lulu Long, Shihong Tian, Yongchang Zhao, Xiaoxiao Zhang, Wen Luo, Xiaojiang Yao
Summary: In this study, we enhanced the catalytic activity and SO2 tolerance of MnCeOx catalyst by modifying it with Nb5+ and Fe3+ co-doping. This improvement was achieved by optimizing the surface acidity, surface adsorbed oxygen, and electronic interaction of the catalyst. The NbFeMnCeOx catalyst exhibited excellent resistance to SO2, with less SO2 being adsorbed and easier decomposition of ammonium bisulfate (ABS) formed on its surface, as well as fewer sulfate species formed. Additionally, we proposed a possible mechanism for how Nb5+ and Fe3+ co-doping enhances the SO2 poisoning resistance of MnCeOx catalyst.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Chemistry, Physical
Yanke Yu, Xianfang Yi, Jiali Zhang, Zhaojian Tong, Changwei Chen, Mudi Ma, Chi He, Jinxiu Wang, Jinsheng Chen, Bingbing Chen
Summary: A series of rhenium-supported TiO2 catalysts demonstrated excellent SO2 tolerance in NH3-SCR reaction due to suitable surface acidity and reducibility. Experimental results and DFT calculations indicated weak SO2 adsorption on the catalysts and little effect of SO2 on the reaction mechanism, which followed the Eley-Rideal mechanism.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
Article
Engineering, Environmental
Ruiyang Chen, Xiaoyu Fang, Junhua Li, Yi Zhang, Zhiming Liu
Summary: In this study, a novel MnCoOx sphere catalyst with high activity and remarkable SO2 tolerance was developed. The mechanism of SO2 poisoning of pure MnOx catalyst was revealed, and it was found that MnCoOx catalyst can maintain high catalytic performance in the presence of SO2.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Energy & Fuels
Zijian Zhou, Lei Liu, Xiaowei Liu, Yue Zhou, Changqing Wang, Jingying Xu, Guozhang Chang, Minghou Xu
Summary: MnOx-based oxides are efficient catalysts for elemental mercury oxidation in flue gas, and combining with CeO2 or CeO2-ZrO2 enhances their catalytic activity. The new MnOx-CeO2-ZrO2 solid solution catalyst showed better Hg-0 oxidation performance compared to the MnOx/CeO2-ZrO2 supported catalyst. Mn4+ and surface active oxygen were identified as the active species in Hg-0 oxidation reactions, and SO2 significantly inhibited the activity of MnOx/CeO2-ZrO2 but had less impact on MnOx-CeO2-ZrO2 solid solution.
Article
Chemistry, Physical
Lusha Zhou, Jinkun Guan, Chenglong Yu, Bichun Huang
Summary: A series of MnOx/SAPO-34 catalysts were synthesized using the ethanol dispersion method, with SAPO-34 as the zeolite carrier with a hierarchical pore structure obtained through facile acid treatment. The NH3-SCR performance of these catalysts showed that MnOx/SAPO-34-0.1 catalyst with ca.15 wt.% Mn loading exhibited optimal catalytic activity and SO2 tolerance at low temperatures, achieving almost 100% NO conversion and over 90% N2 selectivity at 120 degrees C under GHSV of 40,000 h(-1).
Article
Engineering, Environmental
Zhaoyang Fan, Gong Cheng, Jiangning Liu, Yifan Su, Caiqin Feng, Xu Wu
Summary: In this study, two simple model catalysts (Mn3O4 and MnFeOx) were prepared and tested under different temperatures (100, 150, 200, 250 degrees C) in an SCR atmosphere with SO2, followed by regeneration and characterization. The results showed that both catalysts exhibited temperature-dependent deactivation behavior, with the most severe activity loss occurring at 150 degrees C. The FeOx modification protected MnOx species from sulfation to a certain extent and reduced irreversible deactivation.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Environmental Sciences
Yijuan Pu, Pengchen Wang, Wenju Jiang, Zhongde Dai, Lin Yang, Xia Jiang, Zhicheng Jiang, Lu Yao
Summary: The newly prepared CeO2/CNTs-GAC catalyst exhibits high efficiency in low-temperature selective catalytic reduction of NOx by NH3 and excellent SO2 resistance. The addition of CNTs enhances the catalytic performance, inhibits SO2 adsorption, and promotes the formation of oxygen oxidation species.
Article
Engineering, Environmental
Zhuo Yang, Zhongpeng Wang, Wei Liu, Ben Wang, Xinru Luan, Yujia Zhai, Liguo Wang
Summary: A series of MnOx supported on MgAl2O4 spinel catalysts were prepared for low temperature SCR of NOx with ammonia. The Mn0.12/MAS-700 catalyst showed the best denitrification performance, with more than 80% conversion of NO at 150-300 degrees C and higher than 60% N2 selectivity. The addition of Mn species increased the surface acidity of weak acid centers which promoted the catalyst activity.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Engineering, Environmental
Yu Zhang, Ling Zhao, Mengdi Kang, Ziang Chen, Shengjun Gao, Haigang Hao
Summary: This study successfully developed Cu and Zn modified CoAlO catalysts with improved denitration performance and anti-poisoning ability, showing great potential for practical applications at low temperatures. The synergistic interaction between Co and Cu contributes to the outstanding deNOx performance. This work provides a new strategy for the design and fabrication of low temperature CO-SCR catalysts.
CHEMICAL ENGINEERING JOURNAL
(2021)
