Top panel: remaining CH₃NC (from red to green curves) after completing the reaction with H atoms on the surface with the temperature ranging from 20 to 40 K. Middle panel: TPD traces of CH₃NCH₂ ( + 2H) (from red to green curves) are gradually reduced with the surface temperature. Bottom panel: the trace of dimethylamine (CH₃NHCH₃ − + 4H) is not detectable at high temperatures.