Unraveling the Active Phase of Nickel Catalysts in Ethanol Dry Reforming: Insights From Magnetic and Crystallographic Studies

In this study, the ferromagneticresonance (FMR) technique was used to investigate the magnetic structure of nickel-containing xAl₂O₃-[88% ZrO₂-12% CeO₂] catalysts (where x = 5, 20, 50, and 75 mol.%) for ethanol dry reforming (EDR). We have shown that it is possible to determine the deactivation effect of the EDR reaction on the catalysts using FMR spectroscopy. The deactivation of nickel nanoparticles on the catalyst's surface can proceed via two potential pathways: carbonization and sintering. Active carbonization of the nickel-containing catalyst can be detected by a decrease in the FMR signal linewidth, while sintering can be identified from FMR linewidth increase. While, the relative shape of the nickel nanoparticles can be found from the asymmetry parameter of the FMR spectrum.