Infrared Spectroscopy Characterization of the Chemistry of C 4 Hydrocarbons on Pt(111) Single-Crystal Surfaces Ilkeun Lee and Francisco Zaera* Department of Chemistry, University of California, Riverside, CA 92521, USA Supporting Information Figure 1. RAIRS for the uptake of cis- and trans-2-butene on Pt(111) at 80 K. Figure 2. RAIRS for the uptake of butane, 1-butene, and 1,3-butadiene on Pt(111) at 80 K. Figure 3. RAIRS for the thermal chemistry of cis- and trans-2-butene on Pt(111). Figure 4. RAIRS for the thermal chemistry of 1-butene and 1,3-butadiene on Pt(111). Table 1. Peak assignment for the RAIRS of cis-2-, trans-2-, and 1-butenes adsorbed on Pt(111).