EARTH

[3801-11-11] Synthesis, Characterization and Performance of Ceria-based Nanomaterial for Elemental Mercury Removal

Chaofang Li¹, Xingyao Li¹, Libiao Liu¹, ○Weichun Yang^1,2 (1. Central South University, 2. Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution)

Chairman: Jonghyun Lee（Chungnam National University）, Liyuan Chai (Central South University)

Keywords:Ceria-based , Nanomaterial, Elemental Mercury Removal

Nano-ceria material is widely applied for catalysis due to its excellent redox ability. Pure ceria and ceria-based nanomaterials doped with cobalt(Co), copper(Cu), iron(Fe) were synthesized by a one-step hydrothermal method in this paper. XRD, SEM,TEM, nitrogen adsorption-desorption were employed for material characterization. Their performances on elemental mercury removal were studied and the mechanism of Hg⁰ oxidation was discovered. The XRD patterns and TEM images of Co-CeO₂ under different reaction time show that Ce(OH)CO₃ is regarded as eventual reaction precursor of Co-CeO₂ and CeO₂ is gotten after calcination. The formation mechanism assembling-dissolving-nucleation-reassembling is proposed for Co-CeO₂ with lamellar structure. Hg⁰ oxidation performance of the four materials ranks in the order of Co-CeO₂>Cu-CeO₂>Fe- CeO₂> CeO₂ and Hg⁰ removal efficiency of Co-CeO₂ in pure N₂ is as high as 98%.On the other hand, Co-CeO₂ exhibits 100% Hg⁰ removal efficiency in the temperature of 200^OCor 300^OCand the superficial velocity 150000 h^-1 or 300000h^-1 in atmosphere of N₂+ 4%O₂. Moreover, Hg⁰ oxidation is considered to be associated with oxygen vacancy and active oxygen concentration, which can be proved by the results of Raman andH₂-TPR. Therefore, the Mars-Maessen mechanism is assumed to account for Hg⁰ catalytic oxidation.