Oxidative steam reforming of bio-butanol for hydrogen production: effects of noble metals on bimetallic CoM/ZnO catalysts (M = Ru, Rh, Ir, Pd)

•Hydrogen from catalytic oxidative steam reforming of bio-butanol raw mixture.•ZnO-supported catalysts for oxidative steam reforming of butanol–acetone–ethanol.•Stabilization of Co-based catalysts under bio-butanol oxidative steam reforming.•Noble metal added to Co/ZnO improves oxidative steam reforming of bio-butanol.

The influence of the addition of a noble metal (Ru, Rh, Ir or Pd) on the catalytic performance of Co/ZnO was studied with respect to oxidative steam reforming of the bio-butanol raw mixture (butanol/acetone/ethanol = 6/3/1, mass ratio). Bimetallic catalysts, CoM/ZnO (M = Ru, Rh, Ir, Pd) had higher conversion values, decreased deactivation and higher H2 concentration in the outlet gas than monometallic Co/ZnO. However, significant differences were found in both raw mixture conversion and H2 concentrations for the different CoM/ZnO, depending on M. CoRh/ZnO presented the best catalytic behavior (65.1 mol% hydrogen in the outlet after 100 h of reaction at 500 °C with 84% conversion). Characterization of catalysts post-reaction by Raman spectroscopy and TPO showed that less ordered and less abundant carbonaceous deposits were formed over bimetallic catalysts than over the monometallic one; CoRh/ZnO had the lowest amount of such coke.

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