Efficient hydrogen production from bio-butanol oxidative steam reforming over bimetallic Co–Ir/ZnO catalysts

Abstract

This paper reports, for the first time, hydrogen production from oxidative steam reforming of a bio-butanol raw mixture (n-butanol–acetone–ethanol = 6 : 3 : 1, mass ratio). The process was carried out over new bimetallic Co–Ir/ZnO catalysts using air as an oxidant. The behaviour of bimetallic catalysts was compared with that of monometallic ones. Bimetallic catalyst Co–0.3Ir/ZnO (7 wt% Co, 0.3 wt% Ir) showed higher catalytic performance than monometallic samples, giving higher hydrogen concentration in the outlet gas and lower by-product formation. Moreover, the addition of 0.3 wt% Ir to Co–ZnO prevented the formation of carbon deposits and decreased their degree of graphitization. Addition of more iridium (1 wt% Ir) did not improve the catalytic behaviour. Several techniques, such as N₂ adsorption, XRD, TPR, HRTEM, TG-DTG, XPS and Raman spectroscopy, were used for characterizing the fresh and used catalysts.