Production of propylene glycol (1,2-propanediol) by the hydrogenolysis of glycerol in a fixed-bed downflow tubular reactor over a highly effective Cu–Zn bifunctional catalyst: effect of an acidic/basic support

Very high glycerol conversion of 98.5% with ∼89% selectivity to propylene glycol was achieved at a very low pressure (0.72 MPa) over Cu–Zn/MgO catalyst for vapor phase hydrogenolysis of glycerol. Uniformly distributed partially reduced copper species (Cu ₂ O, CuO, and Cu ⁰ ) and higher basicity of the catalyst were the governing factors for higher selectivity to propylene glycol.