Catalytic partial oxidation of methane over nanosized Rh supported on Fecralloy foams

• Highly dispersed Rh catalysts on Fecralloy foams with or without washcoat layer.
• Homogeneous distribution of Rh nanoparticles obtained by electrodeposition.
• Prolonged CPO operation induces sintering of Rh in direct contact with Fecralloy.
• AlPO4 or γ-Al2O3 washcoat on Fecralloy enhance Rh dispersion and stability.
• Preservation of steam reforming activity is crucial to avoid catalyst overheating.

Structured catalysts for the partial oxidation of methane were prepared by supporting Rh nanoparticles onto Fecralloy foams at relatively low precious metal loadings. The investigation was focused mainly on an innovative and straightforward preparation procedure consisting in the direct cathodic electrodeposition of Rh onto foam samples. For the sake of comparison, other Rh-based catalysts were prepared with a more traditional approach, by using the same foams and an AlPO4 washcoat layer. The catalysts were characterized by SEM-EDS, XRD and cyclic voltammetry, to assess the Rh surface area, and tested in the CPO of methane to syngas under self-sustained high temperature conditions at short-contact-time. During prolonged CPO tests the performance of electrochemically prepared catalysts underwent a progressive decline, as compared to stable operation of AlPO4 washcoated catalysts, which was mainly ascribed to sintering of Rh nanoparticles, negatively affecting the activity for methane steam reforming.