High-temperature CO2 methanation over structured Ni/GDC catalysts: Performance and scale-up for Power-to-Gas application

This paper investigates the performance of 25 wt% Ni/GDC catalyst supported on ceramic monolith (MO) and open-cell foam (FO) towards the conversion of CO2 to CH4 at bench-scale level (CO2 flow rate = 78–319 NL·h−1). Both structured catalysts were prepared by the In Situ-Solution Combustion Deposition (IS-SCD) method to coat thin, uniform and high-resistance catalytic layers (Ni/GDC). Catalysts were characterized by XRD, TEM, SEM, and adhesion tests. Temperature profiles in axial and radial direction were registered and discussed. The experimental results highlighted the effect of the geometry of the support on the thermal profile of the catalytic bed and, consequently, on the catalytic performance towards CO2 methanation. For the investigated quasi-adiabatic conditions, the monolith-supported sample enabled a favourable temperature distribution, leading to higher performances (χCO2 = 70.3%; FCH4, OUT = 2.6 NL·cm−3·h−1) compared to the foam-based catalyst (χCO2 = 52.0%, FCH4, OUT = 2.2 NL·cm−3·h−1). Besides, Ni/GDC-MO catalyst showed high stability for 50 h of time-on-stream under daily start-up and shut-down cycles.