INFRARED STUDY OF CARBON-MONOXIDE ADSORPTION AND HYDROGENATION OVER PD-FE CATALYSTS

Carbon monoxide adsorption and hydrogenation over several alumina- and silica-supported Pd and Pd-Fe catalysts have been studied by IR spect roscopy. A higher ratio of linear to bridged CO species was observed w ith the Pd-Fe/Al2O3 samples. No methane formation was detected with th e silica-supported catalysts. The Pd-Fe/Al2O3 catalysts exhibited lowe r methanation activity, lower rates of formation and decomposition of the formate species and lower stability and reactivity of the adsorbed carbon monoxide. A mechanism of methane formation is proposed by whic h the formate species that occur on the support interact with hydrogen supplied from the metal by spillover.