Spatially asymmetrical copper dimer in ceria as an efficiently synergistic oxidation catalyst

Schematic illustration of the superiority of unique dimeric structure in catalytic activation in oxidation reaction. • Dual-atom Cu centers are achieved with H 2 reduction-He annealing treatment • Cu dimer is revealed as one Cu embedded into CeO 2 lattice and another Cu supported on surface • Cu dimer enhances the synergy between O 2 activation and catalytic oxidation • The Cu dimer demonstrates robust activities for auto emission control and fuel cell application Accurate and facile construction of atomically dispersed active sites is fundamentally important in heterogeneous catalysis. Herein, by applying a unique H 2 -He pretreatment, we successfully synthesize spatially asymmetrical dimeric Cu stabilized by CeO 2 . Integrated microscopic and spectroscopic characterizations, together with DFT calculations have revealed the redispersion of Cu species on CeO 2 support is accompanied by the formation of Cu dimers with one Cu atom embedded into CeO 2 lattice and the neighboring Cu atom supported on-top. The obtained dual-Cu atom catalyst demonstrates its general applicability in emission control scenarios or hydrogen fuel cell for automobile applications with excellent performances. Ab initio calculations reveal that such dimeric Cu sites on CeO 2 promote reactant adsorption and lattice oxygen activation, owing to the synergistic effect of unique dimeric Cu structure. This work highlights the great potential of gas pretreatment in the fabrication of dual-atom catalysts, which is widely applicable to active site modulation in advanced oxidation catalysts.