Novel Ni–Ru/CeO2 catalysts for low-temperature steam reforming of methane

Upgrading of biogas and biomethane into H2-rich streams by steam reforming is regarded as an effective strategy to reduce fossil fuel consumption contributing to the transition towards a green energy system. In this context, novel reactor configurations such as membrane reactors appear a promising route for process intensification, but they require novel catalysts more active at low temperatures, stable, and resistant to coke formation. In this work, we prepared and tested structured catalysts characterized by a low Ni content (7 wt%) and a very low Ru content (≤1 wt%) supported on ceria and deposed onto SiC monoliths. Catalysts were tested at low temperatures (<600 °C), i.e. at temperatures suitable for applications in Pd-based membrane reactors. Fresh and used catalysts were characterized by ICP-MS, N2 physisorption, XRD, TEM, SEM-EDS, XPS and H2-TPR to identify the physicochemical properties affecting the catalytic activity. The catalysts showed good activity towards methane reforming, stable performance, and good resistance to coke formation. Ruthenium affects both the intrinsic catalytic activity and the resistance to the inhibiting effect of steam on the reaction rate. This is related to improved redox properties due to the intimacy between the active metals and their strong-metal-support-interaction with the ceria. Finally, our catalysts show self-activation under reaction conditions, which is an interesting property for applications.