摘要 |
PROBLEM TO BE SOLVED: To obtain a compsn. having superior NOx controlling ability by comprising an acidic oxide support, an alkali metal and/or alkaline earth metal or a mixture thereof, a transition metal oxide, and a transition metal selected from the group Ib and/or IIb or palladium. SOLUTION: The compsn. for lowering an NOx discharging amount in FCC process comprises an acidic oxide support, an alkali metal and/or alkaline earth metal or a mixture thereof, a transition metal oxide having oxygen storage capability, and a transition metal selected from the group Ib and/or IIb of the Periodic Table or palladium. The acidic oxide support preferably contains silica alumina. Ceria is the preferred oxygen storage oxide. Cu and Ag are preferable transition metals of the I/IIb group. By the compsn, an amount of NOx gas discharged can be lowered to promote CO combustion. |