STUDIES ON PTXSNY BIMETALLICS IN NAY .1. PREPARATION AND CHARACTERIZATION

A series of materials containing 1.7 wt% Pt and with Pt/Sn atomic rati os varying from 2.25 to 0.6 were prepared using NaY support. The metho d used to form PtSn bimetallic is based on the reaction of tetramethyl tin with hydrogen covering performed Pt particles. Different technique s such as H-2 chemisorption, CO chemisorption, IR spectroscopy, TEM an d STEM-EDX analysis, and XPS were used to characterize these materials . It appears that H, and CO chemisorption are depressed with the addit ion of tin and that part of the tin is alloyed with Pt to form a bimet allic. The bimetallics so formed are rather heterogeneous; neither CO chemisorption and IR spectroscopy nor XPS gives clear evidence of a po ssible change in the electronic properties of Pt with the addition of tin. (C) 1995 Academic Press, Inc.