Quantum chemistry study on catalytic mechanism of Ca on NO-char heterogeneous reaction

The catalytic mechanism of Ca on NO-char heterogeneous reaction was investigated by employing quantum chemical calculation in this paper. The kinetics and thermodynamics of all elementary reactions of NO reducing by char and Ca were studied by the QCISD (T)/6-311G (d, p)//UB3LYP/6-31G (d) method. The results show that activation energy of NO-Ca reaction is much lower than that of NO-char reaction, which are 109.82 kJ/mol and 245.35 kJ/mol, respectively, which indicates that NO reduction efficiency of Ca is much higher than that of char. On the other hand, the thermodynamics of CaO-C reaction was calculated by the UB3LYP/6-31G (d) method. The results show that Δ G of CaO-C reaction (reaction of CaO and char) is approximately -1000 kJ/mol at high temperature, which indicates that Ca can be refreshed easily and rapidly by char at high temperature.