Kinetics investigation on the reduction of NO using straw char based on physicochemical characterization

► Straw char prepared at 1073 K holds the most developed microstructure, the best combustion activity, and the highest NO reduction rate. ► A transition temperature from dynamic-control to diffusion-control is found around 1173 K. ► The apparent activity energy E of char-NO reaction is in the range of 89.78-95.41 kJ mol−1, affected inconspicuously by the char-preparing temperature. ► The reaction orders of NO and char concentration are 0.89 and 1 respectively.