Steam reforming of simulated bio-oil on K-Ni-Cu-Mg-Ce-O/Al2O3: The effect of K

[Display omitted] •K enhanced steam reforming and inhibited methanation on the K-Ni-Cu-Mg-Ce-O/Al2O3.•K modified surface acid-base properties and thus favorable H2O dissociation.•K doping adjusted the Ni2+/Ni° ratio on the K-Ni-Cu-Mg-Ce-O/Al2O3. Steam reforming of simulated bio-oil (ethanol, acetone, phenol, and acetic acid) and phenol has been studied on K-Ni-Cu-Mg-Ce-O/Al2O3 composite catalysts. Complementary characterization techniques, such as nitrogen sorption, XRD, H2-TPR, H2-TPD, CO-TPD, CO-DRIFTS, and in situ XPS, were used to correlate surface structure and functionality to catalytic performance of potassium (K) doped catalysts. K doping of the Ni-Cu-Mg-Ce-O/Al2O3 catalyst created a Ni°/Ni2+ mixed active phase, which not only enhanced steam reforming activity, but also suppressed the methanation reaction. In addition, K doping changed the surface acid-basic properties of the catalyst, which instead favor the gasifcation and water-gas shift reactions. With the combination of these effects, K doping of Ni-Cu-Mg-Ce-O/Al2O3 catalysts led to higher C1 yield and much lower methane formation, favoring hydrogen production in steam reforming of both phenol and simulated bio-oil.