FTIR study of the interaction of CO and CO2 with silica-supported PtSn alloy

Abstract

The interaction between CO2 and the silica-supported PtSn alloy gave rise to an infrared band at 2339 cm−1 which was assigned to the coordination of this molecule to the bimetallic phase. The coadsorption of CO and CO2 indicates that both compete for similar coordination sites on the supported PtSn alloy. A CO singleton vibration frequency at ca. 2054 cm−1 was determined for both Pt/SiO2 and PtSn/SiO2 catalysts. A dilution effect caused by tin in the silica-supported PtSn alloy is proposed. The presence of isolated Pt sites in the particles of this alloy determine their unique capability to coordinate the CO2 molecule in the active sites.