Synthesis of Cu0.5Mg1.5Mn0.5Al0.5Ox mixed oxide from layered double hydroxide precursor as highly efficient catalyst for low-temperature selective catalytic reduction of NOx with NH3

Qinghua Yan; Sining Chen; Cheng Zhang; Dermot O'Hare; Qiang Wang

doi:10.1016/j.jcis.2018.04.099

Synthesis of Cu_0.5Mg_1.5Mn_0.5Al_0.5O_x mixed oxide from layered double hydroxide precursor as highly efficient catalyst for low-temperature selective catalytic reduction of NO_x with NH₃

J Colloid Interface Sci. 2018 Sep 15:526:63-74. doi: 10.1016/j.jcis.2018.04.099. Epub 2018 Apr 26.

Authors

Qinghua Yan¹, Sining Chen¹, Cheng Zhang¹, Dermot O'Hare², Qiang Wang³

Affiliations

¹ College of Environmental Science and Engineering, Beijing Forestry University, 35 Qinghua East Road, Haidian District, Beijing 100083, PR China.
² Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK.
³ College of Environmental Science and Engineering, Beijing Forestry University, 35 Qinghua East Road, Haidian District, Beijing 100083, PR China. Electronic address: qiangwang@bjfu.edu.cn.

PMID: 29723793
DOI: 10.1016/j.jcis.2018.04.099

Abstract

We report a novel NH₃-SCR catalyst Cu_0.5Mg_1.5Mn_0.5Al_0.5O_x synthesized from layered double hydroxides with superior activity in a wide temperature range and improved SO₂ and H₂O resistance comparing to conventional doped Mn/γ-Al₂O₃. This catalyst results in a high NO_x removal efficiency of 87.0-96.6% in the low temperature range of 100-250 °C, much better than Mn/γ-Al₂O₃ (35.0-67.2%). Besides, it exhibits significant resistance to SO₂ and H₂O due to the existence of Cu and Mg. The promoting effects of Cu and Mg are thoroughly investigated using various physico-chemical techniques. The superior NH₃-SCR activity of Cu_0.5Mg_1.5Mn_0.5Al_0.5O_x catalyst can be associated with its high specific surface area, high reducibility of MnO₂ and CuO species, abundance of acid sites, and the well dispersion of MnO₂ and CuO species. The interactions between SO₂ and NH₃, and the degradation mechanism caused by SO₂ were investigated using in-situ DRIFT analysis.

Keywords: Layered double hydroxides; Mn-based catalyst; NH(3)-SCR; Regenerability; Sulfur dioxide.