Simultaneous catalytic oxidation of nitric oxide and elemental mercury by single-atom Pd/g-C3N4 catalyst: A DFT study

Abstract

To realize simultaneous removal of pollutants released from coal-fired power plants, we carried out a theoretical study on catalytic oxidation of NO and Hg0 on the surface of single-atom Pd/g-C3N4 catalyst (Pdsac/g-C3N4), because after NO and Hg0 are converted to NO2 and Hg2+, products can be well absorbed in WFGD by using higher water solubility. Detailed reaction patterns in the mechanisms of Eley-Rideal (E-R), Langmuir-Hinshelwood (L-H), and termolecular Eley-Rideal (TER) were involved in this calculation. We revealed characteristics of catalytic reactions in thermodynamics and kinetics, and it was found most reactions were favorable in thermodynamics, and part reaction paths can take place spontaneously and irreversibly. Kinetics analysis evidenced the chemical reaction rates were all very fast because of short half-lives of reactants and large reaction rate constants. Fitted Arrhenius formula suggested the lowest activation energies of NO and Hg0 oxidation were just 0.46 eV and 1.81 eV, and therefore we speculated that Pdsac/g-C3N4 catalyst should be a potential catalyst for catalytic oxidation of NO and Hg0.