Direct epoxidation of propylene to propylene oxide over RuO2-CuO-NaCl-TeO2-MnOx/SiO2 catalysts

Abstract Multi-metallic RuO 2 -CuO-NaCl-TeO 2 -MnO x /SiO 2 catalysts were investigated for the epoxidation of propylene to propylene oxide (PO) using O 2 under atmospheric pressure. The metallic weight ratio and the total metal loading on SiO 2 support were optimized at Ru/Cu/Na/Te/Mn = 7.14/3.57/1.79/0.175/1.00 and 25.0 wt%, respectively. RuO 2 and CuO were determined to exhibit a critical bifunctional role for PO synthesis. These active sites were assisted by MnO x and TeO 2 to increase PO formation rate and by NaCl to reduce CO 2 formation. With using the Box-Behnken design, a maximized PO formation rate of 1258 g PO  h − 1  kg cat − 1 was obtained by varying O 2 /propylene feed ratio and reaction temperature.