Two different simplified models of coal char were applied to investigate heterogeneous reduction mechanism of N2O by char through density functional theory in quantum chemistry method.Structure and energy of reactants

intermediates and transition states were calculated so as to determine reaction process

and thermodynamic and kinetic analysis were conducted to reveal heterogeneous reaction mechanism.The results showed that the single carbon atom was not suitable as the model of heterogeneous reaction mechanism of N2O by char due to it cannot reflect the adsorption and desorption of N2O molecule in char surface.While the heterogeneous reaction mechanism of N2O by char can be well studied by six rings carbonaceous cluster model.Through three transition states and two intermediates

N2O was reduced to N2

and energy barrier of N2O adsorption on char surface was 51.01 kJ·mol-1

indicating that adsorption process was easy to happen.In addition

the heterogeneous reduction of N2O by char was exothermic and spontaneous reaction at temperature range of 298.15-1500 K

and reaction can take place in one direction owing to reaction equilibrium constant of greater than 105.Furthermore

the reaction was fast at temperature range of 298.15-1500 K

and reaction activation energy was 43.55 kJ·mol-1 with Arrhenius expression of 1.24×1010exp(-5238.15/T).