Realizing efficient operations of Ni-cermet-based fuel cells on hydrocarbons via an in situ self-assembled metal/oxide nano-heterostructured catalyst

Operating Ni-cermet-based fuel cells on hydrocarbons is charming but largely hindered by poor coking tolerance and severe deterioration. Here, we report an effective metal/oxide nano-heterostructured catalyst with a nominal composition of Pr_0.95Ru_0.05O_2-δ (PRO), which is in situ self-assembled to a Pr_0.95Ru_0.05-xO_2-δ oxide frame coated with Ru metallic nanoparticles (denoted as Ru/PRO) under the operation condition. When applied to the Ni-cermet (Ni-YSZ) anodes, the cells achieve decent peak power densities of 1.784 and 1.870 W cm⁻² on CH₄ and C₃H₈ with only 3 % H₂O at 750 °C, respectively. Moreover, the cells with Ru/PRO-coated anode demonstrate excellent durability when operated on CH₄ for ∼ 220 h and C₃H₈ for ∼115 h. It is demonstrated that the Ru/PRO generates hydroxyl species that react with carbon species, followed by the formation of COH intermediates on anode surfaces for removing the coking, as confirmed by experiments and computations.