Ir/Ce0.9Gd0.1O2−x as a new potential anode component in solid oxide fuel cells integrating the concept of gradual internal reforming of methane

Ce0.9Gd0.1O2−x-supported iridium catalyst containing 0.1 wt% Ir was prepared and studied in the steam reforming of methane under water deficient conditions (H2O/CH4 = 0.1) in order to evaluate its potential use as anode material in solid oxide fuel cells directly fed with methane and integrating a gradual internal reforming (GIR) concept. Catalytic activity of Ce0.9Gd0.1O2−x (CGO) and Ir/Al2O3 (0.1 wt% Ir) was also measured. Attention was paid to carbon deposition. Catalysts were characterized by temperature programmed reaction experiments in dry methane (TPR-CH4) followed by mass spectrometry. Adding Ir to CGO was shown to result in a catalyst much more active than CGO and Ir/Al2O3, being stable and extremely resistant to carbon deposition. Different mechanisms and/or rate determining steps are proposed and discussed to explain the observed different catalytic behaviours depending on the catalyst.