Theoretical Insights into Methane Activation on Transition-Metal Single-Atom Catalysts Supported on the CeO₂(111) Surface

Converting methane into high-value-added chemicals is crucial for addressing the energy transition, where novel processes and catalysts are required to improve the selective activation of methane. In this study, we combined density functional theory within the Hubbard correction calculations and the unity bond index-quadratic exponential potential model to investigate methane activation on TM/CeO 2 (111) systems, where TM represents single-adatoms of Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Ir, Pt, and Au. Our results indicate that the most stable TM adatoms on CeO 2 (111) are those that donate more electrons to the surface, thereby reducing the Ce cations from Ce 4+ to Ce 3+ . The first methane dehydrogenation becomes more thermodynamically favored as the TM period increases; that is, the magnitude of both reaction and dissociation energies increases. In contrast, the C–H activation energy barriers, in general, decrease along with the TM period, which is related to the large magnitude of the CH 3 adsorption energy. Thus, our findings offer valuable insights into the exploration of ceria-supported transition-metal single-atom catalysts for methane activation.