Atomically Dispersed Zn-Stabilized Niδ+ Enabling Tunable Selectivity for CO2 Hydrogenation

For a heterogeneous catalytic process, the performance of catalysts could be improved by modifying the active metal with a second element. Determining the enhanced mechanism of the second element is essential to the rational design of catalysts. In this work, Zn was introduced as a second element into Ni/ZrO2 for CO2 hydrogenation. In contrast to Ni/ZrO2, the selectivity of NiZn/ZrO2 is observed to shift from CH4 to CO. A series of structural characterization results reveals that Zn is atomically dispersed in the NiO and ZrO2 phases as NiZnOx and ZnZrOx, respectively during CO2 hydrogenation, stabilizing a higher valence state of Ni (Niδ+) under a hydrogenation atmosphere over Ni−O−Zn site and thus promoting the generation of CO. These findings shed light on the O-mediated bimetallic effect of NiZn/ZrO2 and bring new insight into the rational design of more efficient heterogeneous catalysts