Hydrogen production via aqueous phase reforming of glycerol over Ni-Co/γ-Al2O3 catalysts: Effect of support modification with lanthanides and alkaline earth metals

Abstract

Aqueous phase reforming (APR) of glycerol on Ni-Co/γ-Al2O3 catalysts was evaluated, studying the effects of support modification with promoters (Ca, Mg, La, Ce). Catalysts were characterized by N2 adsorption–desorption, H2-TPR, CO2-TPD, pyridine-TPD, TEM, XRD, XPS and TPO measurements. Catalytic performance tests were carried out in a continuous flow fixed-bed reactor at 225 ◦C, 25 bar, and two WHSV (2.45–4.90 h􀀀 1) with solution of 10 wt% glycerol during 7 h-on-stream; additional tests were done at different temperatures (210–240 ◦C). Catalysts promoted with Ca, Mg, and La showed an enhanced H2 production compared to theunmodified sample at 2.45 h􀀀 1 WHSV, with ≈ 50 % glycerol conversion and a H2 selectivity between 70 and 85%. At 4.90 h􀀀 1 WHSV and 225 ◦C, the Ca-promoted sample reached 660 μmol.h􀀀 1.g-c1a t H2 production, 30 % glycerol conversion, and 80 % H2 selectivity, displaying the best catalytic performance. Raising the reaction temperature to 240 ◦C, H2 production was 840 μmol.h􀀀 1.g-c1a t with Ni-Co/Ca-Al2O3.