(394b) Study of the Surface Reactivity of a Selective Catalytic Reduction (SCR) Catalyst: V2O5

Vanadium pentoxide,V2O5, has been used as catalyst in the Selective Catalytic Reduction (SCR) units in coal-based power plants because of its high catalytic activity, high thermal stability, and SO3 poisoning resistance. The goal of this research is to understand the surface structure and reactivity of V2O5 (001) under post-combustion conditions (flue gas composition, temperature and pressure) using Density Functional Theory (DFT) calculations. This study will be used as a first step in elucidating the mechanism that governs the heterogeneous Hg, As and Se oxidation pathway across V2O5. While most of the previous experimental work has been carried out on supported V2O5, the scope of this work is to investigate the reactivity of unsupported V2O5 with flue gas species (H2O, HCl, Cl2, CO, SOx, NOx, NH3). The thermodynamic stability of partially reduced V2O5(001) surface will be analyzed as a function of oxygen partial pressure at finite temperatures. Ab initio thermodynamics calculations are carried out to investigate the stability of different V2O5 (001) surface terminations as a function of the temperature and partial pressure of the flue gas species H2O, HCl and O2. These results will be used as a guide in the kinetic studies to determine rate constants and reaction pathways.