Article
Engineering, Environmental
Ye Jiang, Tianyu Liu, Wenqian Gao, Hongwei Ge, Zhengda Yang, Riyi Lin, Xinwei Wang
Summary: 3DOM Ce-W-Nb ternary catalysts show excellent NH3-SCR activity, high thermal stability, and durability. The addition of Nb leads to more evenly dispersed active sites and increased specific surface area. The interaction among Ce, W, and Nb species enhances the chemisorbed oxygen, promoting SCR activity, while Nb doping boosts NH3 adsorption and facilitates the generation of active NOx species, accelerating the reaction rate.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Environmental Sciences
Zhi-Bo Xiong, Zhen-Zhuang Li, Yan-Ping Du, Cheng-Xu Li, Wei Lu, Su-Le Tian
Summary: The optimal ignition temperature of 500 degrees C plays a crucial role in the interaction of cerium and tungsten species, leading to an enhancement in catalytic performance. Increasing the ignition temperature from 150 degrees C promotes interactions of species in the catalyst, suppresses the formation of WO3, and refines the crystalline structure. The catalyst ignited at 500 degrees C exhibits the highest surface area, concentration of Ce species, and Bronsted acid sites, resulting in superior NH3-SCR activity.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Energy & Fuels
Xiaofeng Wang, Yang Xu, Zhe Zhao, Jianbin Liao, Chen Chen, Qingbo Li
Summary: This review summarizes the development of zeolite catalysts in the SCR reaction, including Cu, Fe, Mn and other metal-exchanged zeolites. The study discusses the active sites of different metal-exchanged zeolites in NH3-SCR reaction, emphasizes the role of second metals and metal oxides, and effects of preparation methods and topologies. Challenges and further perspectives of metal-exchanged zeolites in NH3-SCR reaction are proposed to enhance the efficiency of NOx removal.
Article
Chemistry, Multidisciplinary
Anqi Dong, Zhi Yang, Weichao Wang
Summary: This study successfully achieved low-temperature NH3 oxidation by synthesizing mixed-phase catalysts SmMn2O5/Cu-SAPO34. The physicochemical properties of the catalysts were analyzed using characterization methods, and it was found that the internal SCR mechanism is the main reason for the improved conversion and selectivity.
Article
Energy & Fuels
Hanzi Liu, Yi Zhang, Haiming Wang, Changfu You
Summary: A new catalyst (Fe-Ni-W exchanged zeolite) has been reported to extend the application range of SNCR at lower temperatures, increasing NOx conversion rates. Optimization of catalyst usage conditions has led to achieving maximum efficiency at 700 degrees Celsius.
Article
Energy & Fuels
Xiangbo Feng, Baorui Wang, Ge Gao, Shan Gao, Chong Xie, Jian-Wen Shi
Summary: In this study, a series of Mn-Co mixed metal oxides (MnyCo3_yOx) were prepared using ultrasonic technology and hydrothermal treatment, and their denitration performance in selective catalytic reduction (SCR) with NH3 was evaluated. The results showed that MnyCo3_yOx had significantly better SCR de-NOx performance compared to single metal oxides (MnOx or CoOx). This improvement was attributed to the strong interaction between MnOx and CoOx, which reduced crystallinity, increased surface area, facilitated redox cycling, enhanced reducibility and surface acid sites, and accelerated the reaction between adsorbed NOx species and coordinated NH3. This work suggests that building a strong interaction between catalyst components can improve de-NOx performance.
Article
Engineering, Environmental
Yuanyuan Liu, Fengyu Gao, Songjin Ko, Chengzhi Wang, Hengheng Liu, Xiaolong Tang, Honghong Yi, Yuansong Zhou
Summary: This study successfully designed a CoMn2O4/W-TiO2 catalyst with excellent resistance to H2O by introducing tungsten as a promoter for efficient NH3-SCR reaction, showing promising practical applications.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Environmental
Yuqing Pan, Na Li, Ke Li, Shiyuan Ran, Chenyang Wu, Qulan Zhou, Jiyuan Liu, Shuzhou Li
Summary: This study reports a Fe2O3/amorphous SiO2 catalyst with high low-temperature activity for CO-SCR. Experiments and density functional theory (DFT) calculations provide direct evidence that an optimal content of oxygen vacancy enhances the low-temperature NO conversion ratio and N2 selectivity of Fe2O3-based catalyst. Compared with conventional defect engineering, the alpha-Fe2O3 (1 1 0) facet enables an oxygen vacancy generation-filling cycle in the CO-SCR reaction, following Mars-van Krevelen (MvK) mechanism.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Hao Sun, Soo-Jin Park
Summary: MnOx/CeO2 composites have shown outstanding catalytic performance in the SCR of NOx with NH3, but they have deficiencies in thermal stability and reduction efficiency. Constructing MnOx/CeO2 with other semiconductors is an effective strategy to further improve catalytic performance.
Article
Energy & Fuels
Shiyuan Ma, Wenqian Gao, Zhengda Yang, Riyi Lin, Xinwei Wang, Xinbo Zhu, Ye Jiang
Summary: Ce20Nb20Ti catalyst showed excellent NH3-SCR activity and great resistance, attributed to strong interaction among Ce, Nb, and Ti species and their effects on the catalyst surface.
JOURNAL OF THE ENERGY INSTITUTE
(2021)
Review
Chemistry, Applied
Jongsik Kim, Somin Lee, Dong Wook Kwon, Heon Phil Ha
Summary: Rare earth metal vanadates have shown promise for converting NOX to N-2 at high temperatures, but face limitations in catalytic activity due to weak hydrothermal stability, low N-2 selectivity, and limited active sites. This study demonstrates the efficacy of structurally modifying vanadate with additional rare earth metals to generate bimetallic vanadates with improved reactivity and stability.
Article
Engineering, Environmental
Jiafan Cheng, Weiman Li, Xiaoze Wang, Haidi Liu, Yunfa Chen
Summary: This study focused on the fabrication of catalytic fibers for NH3-SCR and investigated the impact of different inorganic supports, preparation methods, and loading weight of V2O5 on their performance. The catalytic aluminum silicate fiber prepared by a sol-gel method showed the best SCR performance. The results are significant for the application of catalytic fibers.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Physical
Katarzyna Swirk, Ye Wang, Changwei Hu, Li Li, Patrick Da Costa, Gerard Delahay
Summary: ZrO2 catalysts promoted by copper and iron were prepared using one-pot synthesis with urea. Characterized by various methods, the Fe-Zr sample showed the most promising results in NH3-SCR, being active and highly selective to N-2, especially in the presence of SO2.
Article
Biochemistry & Molecular Biology
Shun Li, Zuquan Zheng, Zhicheng Zhao, Youling Wang, Yao Yao, Yong Liu, Jianming Zhang, Zuotai Zhang
Summary: CeO2-MnO2 nanocomposites show excellent low temperature NH3-SCR activity, reducing NOx efficiently at temperatures ranging from 150 to 300 degrees Celsius. The outstanding performance is attributed to the strong synergistic interaction between CeO2 nanoparticles and MnO2 nanoflowers, as well as the high surface area and intimate contact.
Article
Chemistry, Physical
Daobing Shu, Tianhu Chen, Haibo Liu, Heng Xie, Xuehua Zou, Ping Zhang, Can Wang, Zhengyan Han, Dong Chen
Summary: This study synthesized a series of novel and superior xFe-Ce-V catalysts and systematically investigated their performance in ammonia-selective catalytic reduction of nitrogen oxides (NH3-SCR) for the first time. Introducing Ce significantly improved the catalyst's activity, selectivity, and resistance to water and SO2, with 0.75Fe-Ce-V exhibiting the best de-NOx performance. The introduction of Ce increased the surface adsorbed oxygen, BET surface area, and acidity, while promoting the formation of intermediate species, thereby enhancing the catalyst's activity. Both the Eley-Rideal and Langmuir-Hinshelwood mechanisms were involved in the NO reduction reaction, with Ce enhancing the contribution of the latter.
APPLIED SURFACE SCIENCE
(2023)