THE ROLE OF METHYL RADICALS IN THE REDUCTION OF NO BY CH4 OVER A BA MGO CATALYST/

Under conventional flow conditions at 760 Torr, 4 mol% Ba/MgO is an ef fective catalyst for the reduction of NO by CH4. The conversion of NO at 700 degrees C is increased ca. threefold when O-2 is added to the s ystem. When reactions are carried out at 500 mTorr, CH3 . radicals are detected in the gas phase over the catalyst with O-2 as the oxidant, but not with NO as the oxidant. Moreover, CH3 . radicals appear to rea ct with NO, presumably to form CH3NO, which is believed to be an inter mediate in the reduction reaction. The positive effect of O-2 can thus be explained by its role in the generation of CH3 . radicals.