Highly Stable Pt/CeO₂ Catalyst with Embedding Structure toward Water-Gas Shift Reaction

Area of Science:

• Heterogeneous Catalysis
• Materials Science
• Surface Chemistry

Background:

• Strong metal-support interaction (SMSI) is crucial for catalyst stability and performance.
• The precise origin and mechanisms of SMSI remain incompletely understood.
• Understanding SMSI is key to designing advanced catalytic materials.

Purpose of the Study:

• To investigate the origin of SMSI using a model Pt/CeO2 catalyst.
• To elucidate the role of specific crystallographic planes of CeO2 in SMSI.
• To correlate interfacial structure with catalytic activity and stability.

Main Methods:

• Synthesis and characterization of Pt/CeO2 catalysts on (110) and (100) CeO2 planes.
• Experimental techniques including in-situ/operando spectroscopy and microscopy.
• Density Functional Theory (DFT) calculations for electronic structure and reaction pathways.

Main Results:

• Discovery of a Pt cluster embedding structure within the CeO2(110) lattice (3-4 atomic layers).
• Observation of enhanced electron transfer and formation of a Pt-O-Ce3+ interfacial structure on CeO2(110).
• Pt/CeO2(110) exhibits superior activity (15.76 molCO gPt-1 h-1) and stability (120h) for the water-gas shift reaction compared to Pt/CeO2(100).

Conclusions:

• The embedding structure at the Pt/CeO2(110) interface is intrinsic to SMSI and enhances catalyst stability.
• Interfacial sites act as active centers for the water-gas shift reaction, promoting CO adsorption and H2O dissociation.
• This study provides fundamental insights into SMSI, paving the way for designing highly stable and active heterogeneous catalysts.