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 (GDC) supported Ni catalysts. Ni content varied from 1 to 10 wt% and molar ratio of H2O to CH4 was 2 in feed. A Ni content of about 5 wt% leads to highest formation rates of both hydrogen and CO2. Over 1 wt% Ni/GDC catalyst at 700 °C, the hydrogen yield equals almost 4 for complete CO2 formation. Increasing Ni content leads to decreasing hydrogen yield. A Ni content of about 5 wt% or lower is beneficial for high CO2 selectivity and low carbon deposition associated with high methane conversion. Increased Ni content results in larger Ni particle size and increased carbon deposition.