Process-intensified protonic ceramic fuel cells for power generation, chemical production, and greenhouse gas mitigation

Here, we present protonic ceramic fuel cells (PCFCs) that achieve the internal dry reforming of methane (DRM) at 550°C–650°C to simultaneously generate power, produce syngas or hydrogen as chemical building blocks, and to mitigate two harmful greenhouse gases. We developed an oxide-supported in situ exsolved Ni-Ru catalyst (Sm_0.2Ce_0.7Ni_0.1Ru_0.05O_2-δ, i.e., SDC-Ni-Ru). The in situ exsolved Ru clusters favor the CO₂ activation step, while the Ni clusters promote the CH₄ activation. The synergy between Ni and Ru clusters simultaneously improves the CH₄ and CO₂ activation, enhancing the DRM activity. Additionally, we discovered that the Ru clusters alter the DRM pathway, favoring the formation of monodentate carbonate species, which subsequently accelerates the oxidization of −CH∗ species on Ni clusters and improves the coking tolerance. The PCFCs equipped with this SDC-Ni-Ru internal DRM catalyst attain exceptional and durable power densities using a mixture of CH₄ and CO₂ as the fuel, setting a record for DRM-PCFCs.