La1.6Ba0.4NiO4-x%BaO(x = 5–20) composites are in-situ prepared and used for NO decomposition.
La1.6Ba0.4NiO4-20%BaO shows N2 yield of 57% at 923 K and can last for at least 500 h.
La1.6Ba0.4NiO4-20%BaO shows N2 yield of 51% at 923 K at molar ratio of O2 to NO equals 1:5.
BaO plays an important role in NOx transportation and storage, favoring the progress of the reaction.