Nanostructured materials with highly dispersed Au–Ce0.5Zr0.5O2 nanodomains: A route to temperature stable Au catalysts?

Abstract

Our strategy to inhibit Au(0) growth with temperature involves the preparation of ultrafine Au clusters that are highly dispersed and strongly interacting with a thermally stable high-surface-area substrate. Temperature-stable Au-cluster-based catalysts were successfully prepared through the controlled synthesis of 3.5 nm Ce_0.5Zr_0.5O₂ colloidal building blocks containing tailored strongly bound Au-cluster precursors. With the objective of stabilizing these Au clusters with temperature, grain growth of Ce_0.5Zr_0.5O₂ nanodomains was inhibited by their dispersion through Al₂O₃ nanodomains. High surface area Au–Ce_0.5Zr_0.5O₂–Al₂O₃ nanostructured composites were thus designed highlighting the drastic effect of Au cluster dispersion on Au(0) cluster growth. High thermal stability of our Au(0)-cluster-based catalysts was shown with the surprising catalytic activity for CO conversion observed on our nanostructured materials heated to temperatures as high as 800 °C for 6 h.