Ideal Co-NiO solid solution with excellent low-temperature propene catalytic combustion performance

Abstract

Doping engineering of transitional metal oxides offers a great opportunity to further optimize the performance of corresponding catalysts. Here, we presented a solid-state co-precipitation routine to synthesize the Co-NiO ideal solid solution, where Co atoms achieved nearly atomically isolation in the NiO lattice matrix. Remarkably a clear correlation was established between the reactivity for propene combustion and the Co dopant amounts, with the propene combustion rate increasing proportionally to the Co dopant amounts. The homogeneously dispersed Co single atoms or tiny CoO_x nanoclusters ensure this linear relationship. More importantly, due to the emergence of Co single atoms and CoO_x nanoclusters with a lower coordination number, significant propene adsorption and subsequent C = C bond dissociation were observed in this Co-doped NiO, which improved the propene combustion reaction rate. Therefore, this solid-state co-precipitation strategy provides an effective doping route for building an ideal doped solid solution.