Potential energy profiles for the NÂ +Â HOCO reaction and products of the chemically activated reactions NÂ +Â HOCO and HÂ +Â HOCO

► The N + HOCO reaction produces a chemically activated HOC(O)N intermediate that dissociates via two competing pathways. ► The ultimate product of the N + HOCO reaction is mostly OH + NCO rather than the energetically favored 3NH + CO2. ► While the barrier leading from the HOC(O)N intermediate to 3NH + CO2 is lower than that leading to OH + NCO, the chemically activated HOC(O)N intermediate reacts more rapidly to form OH + NCO. ► The chemically activated HC(O)OH (formic acid) intermediate formed from H + HOCO forms mostly CO + H2O, not CO2 + H2.