Screening of Metal Oxidesfor Hg⁰Capture

Fossil fuel related industriesare the major anthropogenic sources of Hg⁰ emission. Due to awareness of the detrimental impact, there is an increasing interest in discovering potential materials for Hg⁰ removal. In this paper, the first-row transition metals (from V to Zn), Mo and rare earth metals (La and Ce) in the oxidation states supported by γ-Al₂O₃werepreparedand studied as potential candidates for Hg⁰ capture. Based on evolution of the parameters of enthalpies (ΔH), Gibbs free energy (ΔG), adsorption peaks (T_a, _peak), maximumHg⁰ capture efficiencies (μ_max) and activation energy (E_a)etc, the samples of Cr, Ni, Fe, Mn, Co, Ce and Cu showed better performancesfor Hg⁰ capture amongst the 11 metal oxides. The results also indicated that MoO₃ has potential to promote Hg⁰ capture since the activation energy is relatively low. Consequently, most of the Mo-based binary metal oxides have relatively high Hg⁰ removal efficienciescoupled with lowactivation energies. Particularly, the binary metal oxides of CrMo, MnMo, CuMo, CeMo andCoMo could be selected as appropriate candidates for Hg⁰ capture within specifictemperature windows.