Perovskite lattice oxygen contributes to low-temperature catalysis for exhaust gas cleaning.

ABSTRACT: A Pd catalyst supported on Ba-substituted LaAlO₃ perovskite (Pd/La_0.9Ba_0.1AlO_3-δ ) was investigated for NO reduction at low temperature by propylene, which revealed that Pd/La_0.9Ba_0.1AlO_3-δ has remarkably higher activity than other Pd catalysts at low temperatures (≤573 K) for NO reduction by propylene. To elucidate the surface reaction pathway, transient response tests were conducted using ¹⁸O₂. Also, X-ray photoelectron spectroscopy (XPS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) measurements were conducted. Comparison with a Ba-impregnated catalyst (Pd/Ba/LaAlO₃) demonstrated that Pd/La_0.9Ba_0.1AlO_3-δ shows higher activity for the formation of oxygenated species (C _x H _y O _z ) as an intermediate for NO reduction because the surface lattice oxygen has improved mobility via Ba²⁺ substitution in LaAlO₃. Therefore, Pd/La_0.9Ba_0.1AlO_3-δ have high activity for NO reduction, even at low temperatures in a humid condition.

SUBMITTER: Higo T 

PROVIDER: S-EPMC9067026 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature