Effect of Ni content on hydrogen production via steam reforming of methane over Ni/GDC catalysts

Steam reforming of methane was studied over gadolinia-doped ceria (CDC) supported Ni catalysts. Ni content varied from 1 to 10wt% and molar ratio of H(2)O to CH(4) was 2 in feed. A Ni content of about 5wt% leads to highest formation rates of both hydrogen and CO(2). Over 1 wt% Ni/GDC catalyst at 700 degrees C, the hydrogen yield equals almost 4 for complete CO(2) formation. Increasing Ni content leads to decreasing hydrogen yield. A Ni content of about 5 wt% or lower is beneficial for high CO(2) selectivity and low carbon deposition associated with high methane conversion. Increased Ni content results in larger Ni particle size and increased carbon deposition. (C) 2008 Elsevier B.V. All rights reserved.