Catalytically efficient Ni-NiO<sub>x</sub>-Y<sub>2</sub>O<sub>3</sub> interface for medium temperature water-gas shift reaction.

Xu, Kai; Ma, Chao; Yan, Han; Gu, Hao; Wang, Wei-Wei; Li, Shan-Qing; Meng, Qing-Lu; Shao, Wei-Peng et al. · Nat Commun · 2022

basic_science · Level V

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Abstract

The metal-support interfaces between metals and oxide supports have long been studied in catalytic applications, thanks to their significance in structural stability and efficient catalytic activity. The metal-rare earth oxide interface is particularly interesting because these early transition cations have high electrophilicity, and therefore good binding strength with Lewis basic molecules, such as H<sub>2</sub>O. Based on this feature, here we design a highly efficient composite Ni-Y<sub>2</sub>O<sub>3</sub> catalyst, which forms abundant active Ni-NiO<sub>x</sub>-Y<sub>2</sub>O<sub>3</sub> interfaces under the water-gas shift (WGS) reaction condition, achieving 140.6 μmol<sub>CO</sub> g<sub>cat</sub><sup>-1</sup> s<sup>-1</sup> rate at 300 °C, which is the highest activity for Ni-based catalysts. A combination of theory and ex/in situ experimental study suggests that Y<sub>2</sub>O<sub>3</sub> helps H<sub>2</sub>O dissociation at the Ni-NiO<sub>x</sub>-Y<sub>2</sub>O<sub>3</sub> interfaces, promoting this rate limiting step in the WGS reaction. Construction of such new interfacial structure for molecules activation holds great promise in many catalytic systems.