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Indexed by:Journal Papers

Date of Publication:2020-01-01

Journal:CATALYSTS

Included Journals:SCIE

Volume:10

Issue:1

Key Words:core-shell structure; alpha MnO2 nanorods; elemental mercury removal; SO2 resistance

Abstract:Sorbent of alpha MnO2 nanorods coating TiO2 shell (denoted as alpha MnO2-NR@TiO2) was prepared to investigate the elemental mercury (Hg-0) removal performance in the presence of SO2. Due the core-shell structure, alpha MnO2-NR@TiO2 has a better SO2 resistance when compared to alpha MnO2 nanorods (denoted as alpha MnO2-NR). Kinetic studies have shown that both the sorption rates of alpha MnO2-NR and alpha MnO2-NR@TiO2, which can be described by pseudo second-order models and SO2 treatment, did not change the kinetic models for both the two catalysts. In contrast, X-ray photoelectron spectroscopy (XPS) results showed that, after reaction in the presence of SO2, S concentration on alpha MnO2-NR@TiO2 surface is lower than on alpha MnO2-NR surface, which demonstrated that TiO2 shell could effectively inhibit the SO2 diffusion onto MnO2 surface. Thermogravimetry-differential thermosgravimetry (TG-DTG) results further pointed that SO2 mainly react with TiO2 forming Ti(SO4)O in alpha MnO2-NR@TiO2, which will protect Mn from being deactivated by SO2. These results were the reason for the better SO2 resistance of alpha MnO2-NR@TiO2.