Novel shielding and synergy effects of Mn-Ce oxides confined in mesoporous zeolite for low temperature selective catalytic reduction of NOx with enhanced SO2/H2O tolerance

Ran Yan; Sixue Lin; Yonglong Li; Wenming Liu; Yangyang Mi; Changjin Tang; Liang Wang; Peng Wu; Honggen Peng

doi:10.1016/j.jhazmat.2020.122592

Novel shielding and synergy effects of Mn-Ce oxides confined in mesoporous zeolite for low temperature selective catalytic reduction of NO_x with enhanced SO₂/H₂O tolerance

J Hazard Mater. 2020 Sep 5:396:122592. doi: 10.1016/j.jhazmat.2020.122592. Epub 2020 Apr 14.

Authors

Ran Yan¹, Sixue Lin¹, Yonglong Li¹, Wenming Liu¹, Yangyang Mi¹, Changjin Tang², Liang Wang³, Peng Wu⁴, Honggen Peng⁵

Affiliations

¹ Key Laboratory of Jiangxi Province for Environment and Energy Catalysis, College of Chemistry, Nanchang University, 999 Xuefu Road, Nanchang, Jiangxi 330031, China.
² School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
³ Key Lab of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China.
⁴ Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry and Molecular Engineering, East China Normal University, North Zhongshan Road 3663, 200062 Shanghai, China.
⁵ Key Laboratory of Jiangxi Province for Environment and Energy Catalysis, College of Chemistry, Nanchang University, 999 Xuefu Road, Nanchang, Jiangxi 330031, China; Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China. Electronic address: penghonggen@ncu.edu.cn.

PMID: 32298863
DOI: 10.1016/j.jhazmat.2020.122592

Abstract

Nitrogen oxides (NO_x) are a primary source of air pollutants from combustion of fossil fuels. Though Mn-Ce based catalysts exhibit superior low temperature activities, their water and SO₂ tolerance is inferior to other metal oxide catalysts, due to their strong water adsorption and sulfate species formation tendency at low reaction temperatures. Herein, a confinement strategy was adopted to design and synthesize a novel Mn-Ce based catalyst for selective catalytic reduction of NO_x with NH₃. The confined MnCeO_x catalyst was assembled with a simple one pot method, using a mesoporous zeolite (ZSM-5) as the shell and Mn-Ce oxides as the active core (MnCeO_x@Z5). Owing to the zeolite shell's shielding effect and the synergy between the alumina-silica zeolite shell's acidic properties and the mixed oxide cores' redox properties, the novel MnCeO_x@Z5 catalyst displayed enhanced water and SO₂ resistance as compared to the MnCeO_x supported on ZSM-5 (MnCeO_x/Z5) and its precursor (MnCeO_x@Al-SiO₂). Evidently, the zeolite sheath hinders sulfate species formation, and this phenomenon was further investigated by in situ diffuse reflectance infrared Fourier transform spectroscopy (In situ DRIFTS). The novel shielding and acid-redox synergy effect/strategy adopted in this work can be applied to design other high performance deNO_x catalysts for air pollution control.

Keywords: H(2)O-SO(2) resistance; Mesoporous zeolite; Mn-Ce Oxides; NH(3)-SCR; shielding and synergy effects.

Publication types

Research Support, Non-U.S. Gov't