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Three-way conversion (TWC) catalyst supports were prepared having CeO2-ZrO2 solid solution particles uniformly dispersed on γ-Al2O3 as discrete crystallites. The support morphology was characterized using STEM and TEM analysis. TPR and XRD analyses were also carried out on precious metal (PM) containing and PM-free samples before and after aging. These studies were combined with performance measurements which demonstrated the beneficial effects of solid solution formation on TWC catalyst activity. STEM and TEM analysis showed that well-dispersed CeO2-ZrO2 solid solution particles could be formed and simultaneously supported on a high surface area γ-Al2O3 support. For samples calcined up to 600°C, crystallite sizes of ≤50Å were formed as compared to sizes of over 200Å in the aged samples. The TPR studies suggested that for supports calcined up to 600°C most of the CeO2 present was reduced from the Ce4+ to the Ce3+ state in the temperature range 250 - 700°C.