Radiation synthesis of hydrogen cyanide from nitrogen-ethylene system

Abstract The rate of formation of hydrogen cyanide from the nitrogen–ethylene system by 60Co gamma rays was found to depend on irradiation temperature, gas density, gas composition, and the nature of the wall surface of the reaction vessel. Above 100 °C, the G(HCN) value increased with the rise of temperature. Below 100 °C , the G(HCN) value remained constant down to −196 °C. In the temperature range from 400 °C to −196 °C, it increased with reduction of nitrogen gas density. The largest G(HCN) value obtained was 2.0. In certain cases, the wall surface influenced the suppression of hydrogen cyanide formation. As an active species responsible for hydrogen cyanide formation, excited nitrogen molecules are proposed in addition to nitrogen atoms. Excited nitrogen molecules are decomposed to nitrogen atoms with small activation energy or deactivated by collision with other molecules. They play an important role in cyanide formation at low pressures and at high irradiation temperatures.