Influence of Crystal Structure of Y₂O₃-Stabilized Zirconia on Three-way Catalytic Performance of Supported Rhodium Catalyst

The catalytic perfromance of Rh catalysts supported on Y₂O₃-stabilized ZrO₂ with different crystal structures for three-way catalytic (TWC) reactions was investigated. The highest TWC performance was achieved on Rh catalyst supported on 2 mol% Y₂O₃-stabilized ZrO₂ (TZ-2Y) with a mixture of monoclinic and tetragonal phases. The presence of crystallite Rh particles interacting moderately with support, which affects the site geometry and the surface electric state of Rh, was suspected to be responsible for high TWC peformance.