Selective formation of propan-1-ol from propylene via a chemical looping approach

Abstract

A novel chemical looping approach for propan-1-ol production from propylene was investigated. Silver- and gold-based catalysts were prepared, with SrFeO_3−δ perovskite as a catalyst support, and characterised using X-ray diffraction (XRD), electron microscopy (SEM and STEM-EDS), and X-ray photoelectron spectroscopy (XPS). Particles of the catalysts were used in experiments carried out in a packed bed reactor, by passing 5 vol% propylene over the material to generate oxygenated products, with oxygen provided via reduction of the catalyst support, SrFeO_3−δ. The solid particles were subsequently re-oxidised with air in a separate step, closing the chemical loop. Catalysts composed of AgCl and AgAu alloy supported on SrFeO_3−δ gave up to 70–80% stable selectivity towards propan-1-ol over the temperature range 260–300 °C, with little to no formation of the secondary alcohol, propan-2-ol, albeit at low propylene conversion (∼0.5–1.5%). Postulated mechanisms for propan-1-ol formation under chemical looping conditions are discussed, via propylene oxide or allyl alcohol intermediates.