Highly efficient catalytic adsorbents designed by an “adaption” strategy for removal of elemental mercury

Abstract

In the present work, highly efficient catalytic adsorbents for Hg0 removal in both oxygen-rich and deficient atmosphere are developed based on an “adaption” strategy. Firstly, a series of simplified SiO2-based catalytic adsorbents are prepared as model catalysts to gain a deeper insight into the mechanism of the catalytic Hg0 removal process. It is found that for the effective Hg0 removal, the catalytic adsorbent should possess an “assembling” structure involving both Hg0 and oxygen activation sites. An “adaption” strategy is thus implemented for the devise of the catalytic adsorbent, including the functional adaption of different active sites for the reactants and the synergistic function of different active sites. Accordingly, high-efficiency catalytic adsorbent with strong redox property is developed for oxygen-rich atmosphere, while the catalytic adsorbent with high oxygen storage/release property is developed for oxygen-deficient conditions. Moreover, regeneration investigation indicates that the activities of spent catalytic adsorbents are almost fully recovered through the temperature programmed decomposition and desorption (TPDD) process. It is believed that the present “adaption” strategy for catalyst design has guiding significance for the rational and controllable construction of catalysts for other catalytic processes.