The nucleophilic substitutions of chlorobenzene with ammonia and water, leading to aniline and phenol respectively, were investigated using copper-exchanged zeolites. In these reactions, the performance of carbon dioxide as a carrier gas was compared with that of nitrogen. The conversions were slightly influenced; the substitution selectivity, however, increased rapidly with CO2, as the reduction to benzene was decreased substantially. In amination experiments, the benzene formation was decreased by a factor 2-3 with copper-Y. In hydrolysis experiments, the phenol selectivity increased from 85-90% (using N2) to 98-100% (using CO2) with copper mordenite at 400-degrees-C.