Article
Chemistry, Applied
Thi Phuong Thao Nguyen, Ki Hyuck Yang, Moon Hyeon Kim, Yong Seok Hong
Summary: The Fe2O3-promoted V2O5-WO3/TiO2 catalysts showed good N-2 selectivity and suppression of N2O formation in the NH3-SCR reaction. However, an increase in Fe2O3 loading led to a decrease in high-temperature deNOx activity. Surface reactions between N2O and strongly adsorbed NH3 species on the catalysts could greatly suppress N2O formation, starting from as low as 250 degrees C.
Article
Energy & Fuels
Mengxia Qing, Sheng Su, Kun Qian, Liang Liu, Zijun Yin, Song Hu, Yi Wang, Jun Xiang
Summary: This study investigated NH3 adsorption and catalytic performance of V2O5-WO3/TiO2 catalyst under high concentration of CO2 and H2O conditions, showing that CO2 and H2O mainly influence NO conversion by affecting O alpha proportion, V4+ proportion, and NH3 adsorption.
Article
Chemistry, Applied
Thi Phuong Thao Nguyen, Moon Hyeon Kim, Ki Hyuck Yang
Summary: The study investigates the roles of each composition and strongly-adsorbed NH3 in the formation and depression of N2O in NH3-SCR reactions with Fe2O3-promoted catalysts. Fe2O3 promotion allows successful reduction of N2O by strongly-adsorbed NH3 species, proposing a main pathway for depression of N2O formation.
Article
Chemistry, Physical
Wei Zhao, Kai Zhang, Licheng Wu, Qian Wang, Danhong Shang, Qin Zhong
Summary: This study evaluates the effect of self-doping Ti3+ into catalysts on the activity of the catalysts. Various characterization methods such as XRD, XPS, and EPR confirm the presence of Ti3+ and oxygen vacancy, which significantly affect the performance of the catalysts. The results indicate potential for improving low-temperature SCR performance through strategic design of Ti3+ self-doped catalysts.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2021)
Article
Energy & Fuels
Xiaoyu Li, Juan Chen, Chunmei Lu, Guangqian Luo, Hong Yao
Summary: The poisoning effect of Cr on the generation of N2O over gamma-Fe2O3 catalyst during the selective catalytic reduction of NOx with ammonia was observed. The mechanisms of N2O generation at different temperatures were identified, with Cr showing both promotion and inhibition effects on NOx conversion. The formation of FeCr2O4 in the poisoned catalyst was found to be a key factor in enhancing N2O production.
Article
Metallurgy & Metallurgical Engineering
Zeng-hui Su, Shan Ren, Tian-shi Zhang, Jie Yang, Yu-han Zhou, Lu Yao
Summary: The study revealed that doping lead oxide significantly reduces the selective catalytic reduction activity of Ce-Mn/AC catalysts, leading to a decrease in NO conversion. The main reason for this is that the doping of lead oxide reduces the total pore volume and oxygen functional groups of activated carbon.
JOURNAL OF IRON AND STEEL RESEARCH INTERNATIONAL
(2021)
Article
Energy & Fuels
Bolin Zhang, Lifeng Deng, Michael Liebau, Peiqiang Wang, Yingjie Ren, Bo Liu, Chunyun Luo, Roger Glaser, Shengen Zhang
Summary: This study successfully removed the tar species on the catalyst's surface and restored the catalyst's activity through an effective pyrolysis method. The optimized pyrolysis treatment maintained the mechanical properties of the catalyst at a high level and achieved efficient NO conversion and N-2 selectivity at a relatively low temperature range.
Article
Engineering, Environmental
Se Won Jeon, Inhak Song, Hwangho Lee, Joonwoo Kim, Youngchul Byun, Dong Jun Koh, Do Heui Kim
Summary: In this study, a hybrid catalyst was introduced, which exhibited better stability and sulfur tolerance during SO2 aging. The hybrid catalyst achieved the direct migration of ammonium bisulfate from the vanadia domain to the alumina domain through physical contact, rather than gas-phase adsorption. The surface properties of the mixed alumina played an important role in its affinity to ammonium bisulfate and reusability.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Environmental Sciences
Jiahua Xie, Mengyu Li, Zihua Wu, Yiqing Zeng, Shule Zhang, Jing Liu, Qin Zhong
Summary: Activated coke-based catalysts have shown excellent performance in denitration by selective catalytic reduction by NH3, especially at low temperatures. The pre-oxidation process of V2O5/AC catalyst was found to significantly enhance its NH3-SCR activity by promoting the formation of surface-active oxygen species, leading to higher NOx conversion efficiency.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Environmental Sciences
Abrar Inayat, Lisandra Rocha-Meneses, Muhammad Ayoub, Sami Ullah, Ahmad Z. Abdullah, Salman R. Naqvi, Aamir H. Bhat
Summary: This study explores the impact of different Co3O4-based catalysts on the catalytic decomposition of nitrous oxide (N2O) and the conversion of nitric oxide (NO). The results indicate that Co3O4 catalysts prepared through precipitation methods exhibit the highest activity and N2O conversion, even at low reaction temperatures, while commercial nano and powder forms of Co3O4 (CS) perform the poorest. The catalysts lose effectiveness below 400 degrees C, with their activity being greatly influenced by the mixing temperature. The findings offer valuable insights for designing and optimizing catalytic systems for N2O and NO control.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Environmental Sciences
Se Won Jeon, Inhak Song, Hwangho Lee, Do Heui Kim
Summary: Vanadium oxide-based catalysts, such as V/MPTiO2, are promising for SCR of NO with NH3. Addition of W and Mo as promoters to V/MPTiO2 can enhance deNO(x) activities at low temperatures, while Sb tends to have a negative effect on SCR activity. The addition of W and Mo increases the polymerization in V/MPTiO2, generating more reactive vanadia species and leading to enhanced catalytic activity at low temperatures.
Article
Chemistry, Multidisciplinary
Min Seong Lee, Sun- Kim, Bora Jeong, Jin-Woo Park, Taehyo Kim, Jung Woo Lee, Gibum Kwon, Duck Hyun Lee
Summary: Research on coating an NH4+ layer on a vanadium-based catalyst can significantly improve its NOX removal efficiency over a wide temperature range, as well as enhance its proton conductivity, reducing the amount of vanadium oxides and tungsten oxide.
Article
Chemistry, Physical
Liping Sheng, Songda Li, Zhaoxia Ma, Fei Wang, Hu He, Yi Gao, Beien Zhu, Yong Wang, Hangsheng Yang
Summary: The interaction of O-2 with NO reduction pathway greatly affects the NO removal efficiency and N2O formation during the NH3-SCR process over the Pd/CeO2 catalyst. Below 175 degrees C, fast-SCR is the main reaction route for NO removal, while in the temperature range of 175-250 degrees C, NH3 facilitates the reduction of NO but also induces the formation of N2O. Above 250 degrees C, NH3 is severely oxidized leading to excess N2O formation even in the presence of a low amount of O-2.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
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
Chemistry, Multidisciplinary
Geumyeon Lee, Bora Ye, Myeung-jin Lee, Seung-Yeop Chun, Bora Jeong, Hong-Dae Kim, Jungho Jae, Taewook Kim
Summary: This study aims to produce more efficient catalysts for NOx removal by treating the TiO2 support with titanium isopropoxide (TTIP) to increase the number of catalytically active sites and facilitate the dispersal of active materials. The catalyst prepared at a TTIP loading of 5 wt% showed optimal performance due to increased thermal stability caused by high extent of W dispersion and the formation of V(4+) by the reaction of V5+ with surface Ti3+.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2022)