Compositions for reduction of NO.sub.x emissions generated during catalytic cracking process, preferably, a fluid catalytic cracking process, are disclosed. The compositions comprise (i) an acidic metal oxide containing substantially no zeolite, (ii) an alkali metal, alkaline earth metal, and mixtures thereof, (iii) an oxygen storage component, (iv) palladium and (v) a noble metal component, preferably platinum, rhodium or iridium, and mixtures thereof. Preferably, the compositions are used as separate additives particles circulated along with the circulating FCC catalyst inventory. Reduced content of NO.sub.x in an effluent off gas of a full or complete combustion FCC regenerator are accomplished while simultaneously promoting the combustion of CO.