Two highly stable molecules, CH₄ and N₂ were simultaneously activated in a single-stage microwave-heated catalytic reactor to form ammonia, ethane, ethylene, and acetylene at atmospheric pressure. Density functional calculations and micro-kinetics modelling were used to predict the reaction behavior at temperatures ranging from 573 K to 973 K and validated with experimental analysis. The influences of terrace (111) and step (211) sites on K promoted Ru crystals were established in product formation and catalyst coking. NH₃ formation occurs predominantly on the step (211) sites while C₂ product formation can occur on both the sites. It was found that the elementary reaction steps leading to NH₃ synthesis occurs due to the non-thermal effects of microwave irradiation while C₂ products formed simultaneously are due to the thermal effects only. A reaction mechanism is postulated on the catalyst coking and validated experimentally by in-situ regeneration using H₂ and O₂.