Pt-n-O-v synergistic sites on MoOx/gamma-Mo2N heterostructure for low-temperature reverse water-gas shift reaction

Constructing effective synergistic sites between multiple components in supported catalysts is the key to improve catalytic performance. Here the authors utilized the stress of MoO3/gamma-Mo2N structure and the interaction between Pt and support to construct an effective catalytic interface for the 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 MoO3 surface stabilized on gamma-Mo2N. Subsequently, the Pt-MoOx/gamma-Mo2N 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 degrees C). Systematic in situ characterizations illustrate that the MoO3 structure on the gamma-Mo2N surface can be easily reduced into MoOx (2 < x < 3), followed by the creation of sufficient oxygen vacancies. The Pt atoms are bonded with oxygen atoms of MoOx, 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.