Chemisorption of nitric oxide on copper–alumina catalysts

摘要: Nitric oxide chemisorption on an oxidized and H2-reduced surface copper spinel containing 10 wt.% CuO has been studied by IR transmission thermal desorption spectroscopy (TDS). A Cu2+—NO complex nitrito–nitrato complexes were identified, at 308 K the surface. The initial evolution of N2O during dynamic adsorption experiments is related to existence cus Cu+ sites dissociate with NO between 350 450 K, while nitrito decompose simultaneous formation nitrato 600 K. latter groups finally 750 O2.NO chemisorbed metallic Cuo reduced materials On increasing exposure higher temperatures, Cu2+—CO are additionally formed, this being suggestive reoxidation. Initially, active for dissociation as evidenced N2 evolution. Oxygen ad-atoms retained lead bulk correlated presence Cu– sites. metal particles continuously adsorption–desorption cycles TDS profiles progressively approach those observed original sample. This suggests a reconstitution orginal phase even under comparative mild reoxidation conditions. Evidence nitride, CuN, also reported, which can be long still present in material. It believed that these results bear relevance redox processes possibly occurring catalytic reduction nitric oxide.