High catalytic activity and SO2-poisoning resistance of Pd/CuCl2/γ-Al2O3 catalyst for elemental mercury oxidation

A Pd/CuCl2/gamma-Al2O3 catalyst of high activity (up to 87%) and of sulfur-poisoning resistance to SO2 as high as 10,000 ppm was designed for the selective catalytic oxidation of He for the first time. It was found that Pd and CuCl2 function as active sites of Hg-0 adsorption and HCI activation, respectively. The combination of these two phases could improve the regeneration and migration of active chlorine, hinder the simultaneously competitive adsorption of Hg-0 and SO2 on the active sites of CuCl2 and reduce the production and accumulation of sulfates, such as CuSO4. These mechanisms contributed to the outstanding catalytic performance of Pd/CuCl2/gamma-Al2O3.