New catalytic materials were prepared by depositing nanoparticles of 35 different metals as well as their select binary combinations on Al2O3, CeO2, SiO2, TiO2, and ZrO2 supports. Nanoparticles were synthesized by high-throughput pulsed laser ablation (PLA). Catalytic materials were then screened for their selectivities towards the synthesis propylene oxide (PO) from propylene and oxygen using array channel microreactors at 1 atm and 300, 333, and 367 A degrees C. A gas hourly space velocity (GHSV) of 20,000 h(-1) was used at the feed gas composition of 20% O-2, 20% C3H6 and the balance He. Initial screening experiments resulted in the discovery of SiO2 supported Cr, Mn, Cu, Ru, Pd, Ag, Sn, and Ir as the most promising leads for PO synthesis. Subsequent experiments pointed to bimetallic Cu-on-Mn/SiO2, for which the PO yields increased several fold over single metal catalysts. For multimetallic materials, the sequence of deposition of the active metals was shown to have a significant effect on the resulting catalytic activity and selectivity.