SO2和CO氛围下MgO(100)表面催化分解N2O的机理研究

o study the influence of MgO on \ce{N2O} emission in circulating fluidized bed boilers, density functional theory calculations were carried out to investigate the heterogeneous decomposition mechanism of \ce{N2O} on the MgO (1~0~0) surface. The interference of \ce{SO2} and CO on N2O decomposition process was considered. N2O decomposition on the MgO (100) surface is a two-step decomposition process including the O atom transfer process and the surface recovery process. The O atom transfer process is the rate-determining step with the barrier energy of 1.601 eV, while for LH and ER surface recovery processes, the barrier energy is 0.840 eV and 1.502 eV respectively.SO2 has a stronger interaction with the surface active O anion site of MgO (100) surface than that of N2O, and therefore the presence of SO2 will occupy the active site for N2O decomposition, thus hindering N2O decomposition. CO facilitates the surface recovery process but it cannot improve the catalytic ability of MgO (100) surface on N2O decomposition as the O atom transfer process is the rate-determining step of N2O decomposition. Compared with N2O homogeneous reduction by CO, MgO has a limited catalytic effect on N2O reduction with the barrier energy decreasing from 1.691 eV to 1.601 eV.