LAUSR

Purposefully improving the performances of copper-based oxides for Hg0 oxidation was beset with difficulties due to their vagueness of Hg0 oxidation mechanism. In this study, Hg0 oxidation mechanism over CuO/TiO2 was deeply investigated by Hg balance, kinetics and transient reaction. HgO adsorbed on CuO/TiO2 scarcely reacted with gaseous HCl to form HgCl2, so the Mars-Maessen mechanism scarcely contributed to Hg0 oxidation over CuO/TiO2. The reaction order of Hg0 oxidation over CuO/TiO2 at 300-400 oC with respect to the gaseous Hg0 concentration was much less than 1, so neither the Deacon mechanism nor the Eley-Rideal mechanism predominated over Hg0 oxidation over CuO/TiO2. As the contributions of other three mechanisms to Hg0 oxidation over CuO/TiO2 were all ruled out, Hg0 oxidation over CuO/TiO2 mainly followed the Langmuir-Hinshelwood mechanism, which can reasonably explain all the experimental phenomena of Hg0 oxidation over CuO/TiO2.