NO REDUCTION BY ACTIVATED CARBONS .2. CATALYTIC EFFECT OF POTASSIUM

The results of an investigation are reported concerning the NO reducti on activity of different carbons loaded by ion exchange with varying a mounts of a potassium catalyst. The samples were characterized by phys ical adsorption of CO2 (at 0 degrees C) and N-2 (at -196 degrees C) an d by chemisorption of CO2 at 250 degrees C. The reactivity of the pure carbons was determined in both NO and CO2. The catalytic effect of po tassium in NO reduction was evaluated in a fixed-bed flow reactor at a tmospheric pressure using two types of experiments: (i) temperature-pr ogrammed reaction in a NO/He mixture; and (ii) isothermal reaction at 300-600 degrees C; The reaction products were monitored in both cases, thus allowing detailed oxygen and nitrogen balances to be determined. Potassium was found to be an excellent catalyst for the NO reduction by carbon. At temperatures below 600 degrees C, the products of the re action were primarily Na and CO2. The catalytic activity, and thus the concentration of catalytically active sites, is dependent on both cat alyst dispersion and carbon reactivity.