Unraveling structure dynamics in Zr–Fe–Co catalysts during carburization and CO2 hydrogenation using Operando WAXS-MS

We propose operando XRD-MS measurements to elucidate the structural dynamics of Zr-Fe-Co catalysts, promising catalysts for CO2 hydrogenation to sustainable aviation fuels, during carburization and reaction. The study has two main objectives: (i) to resolve the phase evolution of Fe and Co species during carburization, enabling precise determination of crystalline phase transformations, lattice parameter shifts, and crystallite size changes; (ii) to uncover the dynamic structural behaviour of active phases under reaction conditions by directly correlating XRD-derived structural changes with product distribution measured by MS. This integrated approach will provide new insights into the influence of Zr promoter on Fe–Co catalysts, while clarifying the nature of Co and Fe active phases, whether they exist as separate metallic Co and Fe-carbide phases, Fe–Co alloys, or carbide-containing alloys, and their roles in in structural transformations during carburization and under reaction condi