Enhanced bimetallic Rh-Ni supported catalysts on alumina doped with mixed lanthanum-cerium oxides for ethanol steam reforming

Abstract

Enhanced bimetallic Rh (0.25, 0.5, 0.75, 1.0 wt%)-Ni 10 wt%) promoted with La2O3(15 wt%) and CeO2(10 wt%)/alumina supported catalysts for ethanol steam reforming compared to their monometallic counterparts is reported. The larger stability of bimetallic Rh-Ni supported catalysts can be due to a: i) cooperative effect of Rh and Ni activities; ii) larger capacity to gasify the methyl group produced from the decomposition of the intermediaries, iii) non-accumulation of acetate species and, iv) favoring the WGS reaction. The 1%Rh-10%Ni bimetallic catalyst shows the best catalytic performance towards H2 selectivity, operating stability over 144 h of reaction and almost non-carbon formation after 24 h on steam. A significant decrease in the carbon-deposition of the 1%Rh-10 wt%Ni bimetallic catalyst, displaying a 70- and 560-times larger stability than their respective monometallic 1%Rh and 10%Ni counterparts was detected. The study of deactivation/regeneration process of the 1%Rh-10%Ni catalytic system indicates that a reactivation treatment fully recovered the catalytic activity of the deactivated catalyst at least in two regeneration cycles. In both cycles, the bimetallic 1%Rh-10%Ni catalyst was stable until 72 h of reaction appearing as a promising catalyst for the reaction of reforming ethanol at mild temperature conditions.