Hydrogen production from oxidative steam reforming of ethanol over Ir catalysts supported on Ce–La solid solution

Abstract

The Ce1−xLaxO2−δ solid solution (CL) supported Ir (nIr/CL, n = 2, 5 and 10 wt.%) catalysts are studied for H2 production from ethanol oxidative steam reforming (OSR). The Ir dispersion, surface area, oxygen vacancy density and carbon deposition resistance of nIr/CL catalysts are greatly enhanced compared with Ir/CeO2. Among the tested catalysts, 5%Ir/CL shows the best catalytic performance, exhibiting >99.9% ethanol conversion at 400 °C with H2 yield rate of 323 μmol·gcata−1·s−1 and no obvious carbon deposition after used. The 5%Ir/CL catalyst contains the highest amount of reducible interface Ce4+, leading to a strong interaction with surface Ir species at the metal-support interface during the OSR reaction. The strong interaction induces Ir to be well dispersed on the CL support, and is associated with more redox-active sites (interface Ce4+/Ce3+), to guarantee high activity.