“…During an investigation on the properties of La, _,Ce,CuO 4 as catalyst for NO reduction by CO, samples with x = 0, 0.05, 0.10, 0.15, and 0.20 have been examined [1]. They were prepared by mixing the desired amounts of La 2 03 , CuO and CeO2 with ammonium nitrate, following a standard procedure.…”