Pt n -O v synergistic sites on MoO x /γ-Mo 2 N heterostructure for low-temperature reverse water-gas shift reaction.

In heterogeneous catalysis, the interface between active metal and support plays a key role in catalyzing various reactions. Specially, the synergistic effect between active metals and oxygen vacancies on support can greatly promote catalytic efficiency. However, the construction of high-density metal-vacancy synergistic sites on catalyst surface is very challenging. In this work, isolated Pt atoms are first deposited onto a very thin-layer of MoO 3 surface stabilized on γ-Mo 2 N. Subsequently, the Pt-MoO x /γ-Mo 2 N catalyst, containing abundant Pt cluster-oxygen vacancy (Pt n -O v ) sites, is in situ constructed. This catalyst exhibits an unmatched activity and excellent stability in the reverse water-gas shift (RWGS) reaction at low temperature (300 °C). Systematic in situ characterizations illustrate that the MoO 3 structure on the γ-Mo 2 N surface can be easily reduced into MoO x (2 < x < 3), followed by the creation of sufficient oxygen vacancies. The Pt atoms are bonded with oxygen atoms of MoO x , and stable Pt clusters are formed. These high-density Pt n -O v active sites greatly promote the catalytic activity. This strategy of constructing metal-vacancy synergistic sites provides valuable insights for developing efficient supported catalysts.