X-Ray diffraction and transmission electron microscopy were applied to characterize supported PtNi bimetallic systems. It was found that homogeneous alloys were formed. In the cases when the Pt content was greater than 50% the particles have a cubo-octahedral shape. Kinetic results showed that selectivity to isomerization for isopentane increases with Pr content from about 6 to 87% in the composition range between 37 and 100% in atomic Pt. Results are explained on the basis of the variation of percentages of Pt sites present on the (111) faces of the PtNi cubo-octahedrons. A good correlation between B3-type sites of platinum and selectivity was found assuming that there is no segregation surface on the particle alloys.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry