Advanced MnOx/TiO2 Catalyst with Preferentially Exposed Anatase {001} Facet for Low-temperature SCR of NO.

Shengcai Deng, Tingting Meng, Bolian Xu, Fei Gao, Yuanhua Ding, Lei Yu* and Yining Fan,*

^† Key Laboratory of Mesoscopic Chemistry of MOE, Jiangsu Provincial Key Laboratory of Vehicle Emissions Control, Jiangsu Provincial Key Laboratory of Nanotechnology, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, People’s Republic of China

^‡ Jiangsu Provincial Key Laboratory of Environmental Material and Environmental Engineering, School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, People’s Republic of China

Abstract:MnO_x/TiO₂ (anatase) nanosheets (NS) with a preferentially exposed {001} facet was found to be a better catalyst for selective catalytic reduction (SCR) of NO than conventionally employed MnO_x/TiO₂ nanoparticles (NP) with the {101} facet preferentially exposed, affording both high NO conversion and high N₂ selectivity at 80–280 °C. Further investigations indicated that Mn³⁺ as the major species on TiO₂ (NS) was incorporated into octahedral vacancies with a lower polymerization degree, resulting in high catalytic activity for SCR and low activity for NH₃oxidation, thus restraining the undesirable N₂O generation. In comparison, on the surface of TiO₂ (NP), Mn⁴⁺ as the major species was incorporated into tetrahedral vacancies in a highly polymerized state, leading to lower NO conversion and lower N₂ selectivity. The results indicate that it is possible to enhance the low-temperature SCR activity of the catalysts by tailoring the preferentially exposed facet of TiO₂.

ACS Catal., 2016, 6 (9), pp 5807–5815

文章链接: http://pubs.acs.org/doi/abs/10.1021/acscatal.6b01121

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