The positive effect of Ca2+ on cryptomelane-type octahedral molecular sieve (K-OMS-2) catalysts for chlorobenzene combustion

Jingkun Chen; Wanglong Wang; Shuaiying Zhai; Pengfei Sun; Zhongbiao Wu

doi:10.1016/j.jcis.2020.04.071

The positive effect of Ca²⁺ on cryptomelane-type octahedral molecular sieve (K-OMS-2) catalysts for chlorobenzene combustion

J Colloid Interface Sci. 2020 Sep 15:576:496-504. doi: 10.1016/j.jcis.2020.04.071. Epub 2020 Apr 20.

Authors

Jingkun Chen¹, Wanglong Wang¹, Shuaiying Zhai¹, Pengfei Sun², Zhongbiao Wu³

Affiliations

¹ Department of Environmental Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, PR China.
² Department of Environmental Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, PR China; Zhejiang Provincial Engineering Research Centre of Industrial Boiler & Furnace Flue Gas Pollution Control, 388 Yuhangtang Road, 310058 Hangzhou, PR China. Electronic address: sunpf@zju.edu.cn.
³ Department of Environmental Engineering, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, PR China; Zhejiang Provincial Engineering Research Centre of Industrial Boiler & Furnace Flue Gas Pollution Control, 388 Yuhangtang Road, 310058 Hangzhou, PR China. Electronic address: zbwu@zju.edu.cn.

PMID: 32504980
DOI: 10.1016/j.jcis.2020.04.071

Abstract

Herein, K-OMS-2 catalysts with different levels of Ca²⁺ loading were synthesized to investigate the influence of Ca²⁺ deposition on the catalytic oxidation of CB. The micromorphology, redox ability, oxygen species, and surface acidity of the prepared catalysts were analyzed via SEM, HR-TEM, H₂-TPR, O₂-TPD, Py-IR, and GC-MS. After the Ca addition, CB conversion on the catalyst was achieved at <220 °C and the polychlorinated by-product yield decreased significantly. Although CaCO₃ formation on the catalyst surface from Ca²⁺ caused a decline in number and fluidity of the surface lattice oxygen species, no significant impact on surface adsorbed oxygen species content was observed. Furthermore, CaCO₃ reacted with dissociated chlorine species (HCl and polychlorinated products generated in situ), which inhibited chlorine poisoning of the active phase.

Keywords: Calcium deposition; Catalytic oxidation; Chlorobenzene; K-OMS-2.