Elemental Mercury Oxidation over Fe-Ti-Mn Spinel: Performance, Mechanism, and Reaction Kinetics
Elemental Mercury Oxidation over Fe-Ti-Mn Spinel: Performance, Mechanism, and Reaction Kinetics
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Fe-Ti-Mn 尖晶石上的元素汞氧化：性能、机理和反应动力学
DOI：
10.1021/acs.est.6b05023
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发表时间：
2017
影响因子：
11.4
通讯作者：
Yang Shijian
中科院分区：
文献类型：
--
作者：
Xiong Shangchao;Xiao Xin;Huang Nan;Dang Hao;Liao Yong;Zou Sijie;Yang Shijian
由于反应机理和反应动力学的不确定性，Hg 0氧化催化剂的设计和Hg 0氧化程度的预测都受到极大的限制。本文以Fe-Ti-Mn尖晶石为催化剂，研究了Hg 0在Fe-Ti-Mn尖晶石上的氧化反应机理和反应动力学。Hg 0在Fe-Ti-Mn尖晶石上的氧化反应对Hg 0浓度和HCl浓度的反应级数分别约为1和0。因此，Hg 0在Fe-Ti-Mn尖晶石上的氧化主要遵循Eley-Rideal机理（即，Hg 0的氧化速率主要取决于表面Cl·的浓度。H_2O、SO_2和NO不仅抑制了Cl·在尖晶石表面的生成，而且干扰了Hg_0与Cl·在尖晶石表面的界面反应，从而抑制了Hg_0在尖晶石表面的氧化，并可根据动力学参数kE-R预测Hg_0在尖晶石表面的氧化程度。预测结果与实验结果一致。
The design of a high-performance catalyst for Hg0oxidation and predicting the extent of Hg0oxidation are both extremely limited due to the uncertainties of the reaction mechanism and the reaction kinetics. In this work, Fe–Ti–Mn spinel was developed as a high-performance catalyst for Hg0oxidation, and the reaction mechanism and the reaction kinetics of Hg0oxidation over Fe–Ti–Mn spinel were studied. The reaction orders of Hg0oxidation over Fe–Ti–Mn spinel with respect to gaseous Hg0concentration and gaseous HCl concentration were approximately 1 and 0, respectively. Therefore, Hg0oxidation over Fe–Ti–Mn spinel mainly followed the Eley–Rideal mechanism (i.e., the reaction of gaseous Hg0with adsorbed HCl), and the rate of Hg0oxidation mainly depended on Cl•concentration on the surface. As H2O, SO2, and NO not only inhibited Cl•formation on the surface but also interfered with the interface reaction between gaseous Hg0and Cl•on the surface, Hg0oxidation over Fe–Ti–Mn spinel was obviously inhibited in the presence of H2O, SO2, and NO. Furthermore, the extent of Hg0oxidation over Fe–Ti–Mn spinel can be predicted according to the kinetic parameterkE-R, and the predicted result was consistent with the experimental result.