Pd Doped La0.1Sr0.9TiO3 as High-Temperature Water-Gas Shift Catalysts: In-Situ Formation of Active Pd Phase

A series of La0.1Sr0.9Ti1-xPdxO3 with x up to 0.1 were prepared through a modified sol-gel method. Combining X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and Temperature programmed reduction (TPR), we proved that solid solutions formed with a Pd substitution (in the B-sites) of no more than 5 at.%. Further addition of Pd resulted in segregation of PdOx species. An in-depth analysis of in-situ CO adsorption confirmed that the metallic Pd, formed in-situ during the water-gas shift reactions (WGSR), was the major contributor for this reaction. [GRAPHICS] .