Journal ArticleDOI
Fe2O3–CeO2@Al2O3 Nanoarrays on Al-Mesh as SO2-Tolerant Monolith Catalysts for NOx Reduction by NH3
TLDR
Improved reactivity of NH4+ with nitrates following the Langmuir-Hinshelwood mechanism and active NH2 species that directly reacted with gaseous NO following the Eley-Rideal mechanism enhanced the NO x reduction efficiency at low temperatures, paving a way for the development of high-performance SO2-tolerant SCR monolith catalysts.Abstract:
Currently, selective catalytic reduction of NO x with NH3 in the presence of SO2 is still challenging at low temperatures (<300 °C). In this study, enhanced NO x reduction was achieved over a SO2-tolerant Fe-based monolith catalyst, which was originally developed through in situ construction of Al2O3 nanoarrays (na-Al2O3) on the monolithic Al-mesh by a steam oxidation method followed by anchoring Fe2O3 and CeO2 onto the na-Al2O3@Al-mesh composite by an impregnation method. The optimum catalyst delivered more than 90% NO conversion and N2 selectivity above 98% within 250-430 °C as well as excellent SO2 tolerance at 270 °C. The strong interaction between Fe2O3 and CeO2 enabled favorable electron transfers from Fe2O3 to CeO2 while generating more oxygen vacancies and active oxygen species, consequently accelerating the redox cycle. The improved reactivity of NH4+ with nitrates following the Langmuir-Hinshelwood mechanism and active NH2 species that directly reacted with gaseous NO following the Eley-Rideal mechanism enhanced the NO x reduction efficiency at low temperatures. The preferential sulfation of CeO2 alleviated the sulfation of Fe2O3 while maintaining the high reactivities of NH4+ and NH2 species. Especially, the SCR reaction following the Eley-Rideal mechanism largely improved the SO2 tolerance because NO does not need to compete with sulfates to adsorb on the catalyst surface as nitrates or nitrites. This work paves a way for the development of high-performance SO2-tolerant SCR monolith catalysts.read more
Citations
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Journal ArticleDOI
Selective Catalytic Reduction of NOx with NH3 by Using Novel Catalysts: State of the Art and Future Prospects.
Lupeng Han,Sixiang Cai,Sixiang Cai,Min Gao,Jun-ya Hasegawa,Penglu Wang,Jianping Zhang,Liyi Shi,Dengsong Zhang +8 more
TL;DR: This review summarizes the latest SCR reaction mechanisms and emerging poison-resistant mechanisms in the beginning and subsequently gives a comprehensive overview of newly developed SCR catalysts, including metal oxide catalysts ranging from VOx, MnOx, CeO2, and Fe2O3 to CuO based catalysts.
Journal ArticleDOI
SO2-Tolerant Selective Catalytic Reduction of NOx over Meso-TiO2@Fe2O3@Al2O3 Metal-Based Monolith Catalysts
Lupeng Han,Min Gao,Jun-ya Hasegawa,Shuangxi Li,Yongjie Shen,Hongrui Li,Liyi Shi,Dengsong Zhang +7 more
TL;DR: This work supplies a new point for the development of low-temperature SO2-tolerant monolithic SCR catalysts with high N2 selectivity, which is of great significance for both academic interests and practical applications.
Journal ArticleDOI
Synergistic Elimination of NOx and Chloroaromatics on a Commercial V2O5-WO3/TiO2 Catalyst: Byproduct Analyses and the SO2 Effect.
TL;DR: Experimental results indicate that, during the synergistic reaction, the V2O5-WO3/TiO2 catalyst was deactivated at 200 and 250 °C, while the 300 °C was sufficient to durably convert the NO and chlorobenzene (CB) at the turnover frequency (TOF) of 7.23×10-4 s-1 and 1.32×10s-1, respectively.
Journal ArticleDOI
A superior Fe-V-Ti catalyst with high activity and SO2 resistance for the selective catalytic reduction of NOx with NH3.
TL;DR: In Fe-V-Ti catalysts, the charge interaction between Fe2O3 and FeVO4 as well as the electronic inductive effect between Fe and V species resulted in the improvement of SCR activity and N2 selectivity at high temperatures.
Journal ArticleDOI
Insight into the SO2 resistance mechanism on γ-Fe2O3 catalyst in NH3-SCR reaction: A collaborated experimental and DFT study
Yaxin Yu,Wei Tan,Dongqi An,Xiuwen Wang,Annai Liu,Weixin Zou,Changjin Tang,Chengyan Ge,Qing Tong,Jingfang Sun,Lin Dong +10 more
TL;DR: In this paper, the effect of reaction temperature on the catalytic activity in the presence of SO2 was fully revealed, and it was shown that SO2 poisoning of NH3-SCR catalysts at low temperature (< 300 °C is still an austere challenge.
References
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Journal ArticleDOI
Oxygen Vacancy Clusters Promoting Reducibility and Activity of Ceria Nanorods
TL;DR: A direct relationship between the concentration of the larger size oxygen vacancy clusters and the reducibility/reactivity of nanosized ceria was revealed, which may be an important step in understanding and designing active sites at the surface of metal oxide catalytic materials.
Journal ArticleDOI
DRIFT Study on Cerium−Tungsten/Titiania Catalyst for Selective Catalytic Reduction of NOx with NH3
Liang Chen,Junhua Li,Maofa Ge +2 more
TL;DR: Tungstation was beneficial for the formation of Ce(3+), which would influence the active sites of the catalyst and further change the mechanisms of SCR reaction, resulting in the better activity of CeO (2)-WO(3)/TiO(2) compared to that of CeCe(2)/Ti O(2).
Journal ArticleDOI
Dynamic multinuclear sites formed by mobilized copper ions in NO x selective catalytic reduction.
Christopher Paolucci,Ishant Khurana,Atish A. Parekh,Sichi Li,Arthur J. Shih,Hui Li,John R. Di Iorio,Jonatan D. Albarracin-Caballero,Aleksey Yezerets,Jeffrey T. Miller,W. Nicholas Delgass,Fabio H. Ribeiro,William F. Schneider,Rajamani Gounder +13 more
TL;DR: It is demonstrated that under reaction conditions, mobilized Cu ions can travel through zeolite windows and form transient ion pairs that participate in an oxygen (O2)–mediated CuI→CuII redox step integral to SCR.
Journal ArticleDOI
Effect of manganese substitution on the structure and activity of iron titanate catalyst for the selective catalytic reduction of NO with NH3
TL;DR: In this article, the selective catalytic reduction (SCR) of NO with NH3 over manganese substituted iron titanate catalysts was investigated and the Mn substitution amounts showed obvious influence on the catalyst structure, redox behavior and NH3/NOx adsorption ability of the catalysts.
Journal ArticleDOI
Ceria modified MnOx/TiO2 as a superior catalyst for NO reduction with NH3 at low-temperature
TL;DR: In this article, a series of cerium modified MnOx/TiO2 catalysts were prepared by sol-gel method and used for low-temperature selective catalytic reduction (SCR) of NOx with ammonia.