Catalytically efficient Ni-NiO-YO interface for medium temperature water-gas shift reaction.

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 HO. Based on this feature, here we design a highly efficient composite Ni-YO catalyst, which forms abundant active Ni-NiO-YO interfaces under the water-gas shift (WGS) reaction condition, achieving 140.6 μmol g s 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 YO helps HO dissociation at the Ni-NiO-YO 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.