Poly(3-hydroxybutyrate) (PHB), a renewable biological material, was converted to oils and propylene through one-step cerium oxide (CeO2) catalytic reforming. In mild reaction conditions (CeO2:PHB:water = 1:1:4, 240 degrees C, 9 h), high yields of bio-oils (35 wt %) and propylene (17 wt %) were obtained by completely inhibiting the formation of solid residues. The oils contained ketones, esters, chain and cyclic hydrocarbons, ethers, alcohols, and an N-containing compound, with an estimated higher heating value (HHW) of 33.3 MJ/kg. Under the above reaction conditions, the CeO2 exhibited near-perfect reusability, without any requirement of regeneration after 5 reuse cycles.