Stability of Pd_xO_y Particles Supported on Strontium Titanate Perovskite under Three-Way Catalyst Operating Conditions: Implications for Sintering Resistance

Abstract

Self-regenerative materials are keys to the development of stable catalysts used under high temperature condition, e.g., three-way catalyst converters in automobiles. Among others, metal nanoparticles supported on perovskite oxides are promising ones. However, little is known about their atomistic details, which are crucial for understanding and development of thermally stable catalysts. Herein, we present a machine-learning-enhanced density functional theory study of Pd x O y nanoparticles supported on a Sr 3 Ti 2 O 7 (001) surface and demonstrate that supported oxidized Pd particles fulfill the conditions for the self-regenerative catalysts. Under the oxidative condition, the solid-solution reaction of Pd with the support is found to be preferable but is limited to the vicinity of the surface. Furthermore, formation of PdO-like clusters enhances their binding strength to the support, inhibiting the agglomeration (sintering) of the Pd x O y nanoparticles. We present detailed thermodynamic and electronic structure analyses and clarify the roles of the oxide support, cluster size of the oxidized metal nanoparticle, and the metal−support interaction. This work may provide a guideline for the rational design of the thermally stable catalyst against sintering

Improvement of Oxygen Storage Capacity by Charge Transfer via Oxygen Ions in Sr3Fe2–xNixO7.0−δ

“…With the current effort of decarbonization to slow global warming and the related regulation of emission of harmful substances, considerable attention has been focused on the development of renewable energy and exhaust gas purification catalysts for automobiles . Oxygen diffusion and transport properties play important roles in the development of cathodes in solid oxide fuel cells (SOFCs) and three-way catalysts for purifying harmful gases such as nitrogen oxides (NO x ), carbon monoxide (CO) and hydrocarbons (HCs). − …”