In an effort to examine the role of crystal morphology on activity, mesoporous scale defects were introduced into titanium silicalite-1 (TS-1) support materials through the addition of carbon pearls during the synthesis procedure. Catalysts prepared using these support materials were consistently active and stable, with a 0.33 wt% Au catalyst producing 132 g(PO)/h/kg(cat) at 200 degrees C, the highest propylene oxide (PO) rate thus reported, despite relatively high gold loadings and considerable contamination with octahedral titanium species. While activity is high per gram catalyst, activity per gram gold was still relatively low implying that a significant portion of gold deposited on the support surface may be inactive for epoxidation. (c) 2007 Elsevier B.V. All rights reserved.