Catalytically efficient Ni-NiOx-Y2O3 interface for medium temperature water-gas shift reaction

Developing effective and stable catalytic interfaces in the medium temperature region is a practical route to replace the existing water gas shift (WGS) process. Here the authors designed a composite Ni-Y2O3 catalyst achieving the highest WGS activity for Ni based catalysts. 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 H2O. Based on this feature, here we design a highly efficient composite Ni-Y2O3 catalyst, which forms abundant active Ni-NiOx-Y2O3 interfaces under the water-gas shift (WGS) reaction condition, achieving 140.6 mu mol(CO) g(cat)(-1) s(-1) rate at 300 degrees C, which is the highest activity for Ni-based catalysts. A combination of theory and ex/in situ experimental study suggests that Y2O3 helps H2O dissociation at the Ni-NiOx-Y2O3 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.

Automated summary

This study designs a composite Ni-Y2O3 catalyst with abundant active interfaces, achieving the highest activity among Ni-based catalysts and providing a practical route to replace the existing water gas shift process.