In-situ Analysis of Alloy Effects in Low-temperature Methane Dry Reforming in an Electric Field

Methane dry reforming at 373 K in a DC electric field was carried out using Ni/CeO₂ and Ni_0.8Fe_0.2/CeO₂ alloy catalysts, and their alloying effects were investigated in detail using XAFS and in-situ surface spectroscopy. For the Ni catalyst, there was a decrease in the adsorption of carbonate species, an increase in the proportion of bidentate carbonate species, and an observed degradation in activity caused by carbon deposition over time. Conversely, the alteration of electronic state occurring as a result of the ligand effect (electronic interaction among atoms by alloying) on the Ni-Fe catalyst contributed to the stabilization of intermediates involved in rate-determining steps specific to electric-field catalysis. Carbon deposition was less likely to occur, resulting in significantly higher activity when compared to the Ni catalyst.