Role of valency of copper in the direct decomposition of nitrogen monoxide over well characterized La 2x A′ x Cu 1–y B′ y O 4

Catalytic activity is closely related to the valency of copper in the direct decomposition of NO over well characterized La2x A′xCu1-yB′yO4 catalysts (K2NiF4 structure; A′= Sr, B′= Al, Zr, x= 0–1.0, y = 0, 0.2); the formal valency of copper was controlled in the range 1.60–2.30.