Competing pathways for isocyanate loss from Cu(0Â 0Â 1) with co-adsorbed oxygen

► NCO on Cu(0 0 1) is generated via (i) HNCO adsorption or by (ii) C2N2 + O2 co-adsorption. ► Annealing NCO + O/Cu(0 0 1) at 473 K leads to the production of CO2(g)+N(a). ► Annealing NCO + CN + O/Cu(0 0 1) at 473 K leads to the production of CO(g)+CO2(g)+N(a). ► In latter case, the relative yields of CO(g) can be considerably higher than for CO2(g). ► CN(a) in proximity to NCO(a) catalyzes the latter's dissociation into CO(g)+N(a).