Determination of IR extinction coefficients for linear- and bridged-bonded carbon monoxide on supported palladium

摘要: Infrared spectra were obtained of CO adsorber on Pd dispersed four supports: eta-Al/sub 2/O/sub 3/, SiO/sub 2/, 2/-Al/sub and TiO/sub 2/. All catalysts characterized by both H/sub 2/ chemisorption which allowed the calculation surface coverages linearly adsorbed CO, gives a band above 2000 cm/sup -1/, bridged-bonded form, produces below -1/. From these values, integrated absorbances, A, extinction coefficients, epsilon, have been determined for each species first time. For individual catalysts, absorbances coefficients always much higher than i.e., average values A/sub b/ = 85 x 10/sup 7/ cm mol/sup 1/ 3.3 epsilon/sub 4.1 6/ 0.36 Because specially designed ir reactor cell was utilized, also taken under steady-state hydrogenation reaction conditions to form CH/sub 4/. The Al/sub 3/-, 2/-, 3/-supported still exhibited strong bands;more » however, Pd/TiO/sub wafers exhibiting SMSI (strong metal-support interactions) showed no detectable bands although they most active catalyst. Using epsilon in this study, we estimated maximum coverage be less 1% linear 0.1% bridged species.« less