Effect of Al(CO)x complexation on the aluminum oxidation process Original Research Article

A comparison of the AlO B 2Σ+ state population distributions observed for the multiple collision Al+Ar+O3→AlO*(B 2Σ+)+Ar+O2 and Al+nCO+O3→AlO*(B 2Σ+)+nCO+O2 reactive encounters suggests that Al(CO)x adducts are formed via the entrainment of aluminum atoms in CO. The subsequent oxidation of these adducts with O3 produces an AlO B 2Σ+ state population distribution which reflects a smaller reaction exothermicity and shorter range reactive encounter than the oxidation of bare Al atoms. Differences in the observed population distributions are attributed to an Al(CO)2+O3 reaction. This conclusion is also based, in part, on the similarity between the AlO B state population distributions associated with the Al(CO)2+O3 reaction and that previously measured for the Al+N2O multiple collision reactive encounter. This assignment is further supported by matrix isolation studies where only Al(CO)2 has been observed.