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

Liu, Hao-Xin; Li, Jin-Ying; Qin, Xuetao; Ma, Chao; Wang, Wei-Wei; Xu, Kai; Yan, Han; Xiao, Dequan et al. · Nat Commun · 2022

basic_science · Level V

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Abstract

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<sub>3</sub> surface stabilized on γ-Mo<sub>2</sub>N. Subsequently, the Pt-MoO<sub>x</sub>/γ-Mo<sub>2</sub>N catalyst, containing abundant Pt cluster-oxygen vacancy (Pt<sub>n</sub>-O<sub>v</sub>) 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<sub>3</sub> structure on the γ-Mo<sub>2</sub>N surface can be easily reduced into MoO<sub>x</sub> (2 < x < 3), followed by the creation of sufficient oxygen vacancies. The Pt atoms are bonded with oxygen atoms of MoO<sub>x</sub>, and stable Pt clusters are formed. These high-density Pt<sub>n</sub>-O<sub>v</sub> active sites greatly promote the catalytic activity. This strategy of constructing metal-vacancy synergistic sites provides valuable insights for developing efficient supported catalysts.