CARBON-MONOXIDE ADSORPTION BY K/CO/RH/MO/AL2O3 HIGHER ALCOHOLS CATALYSTS

The room temperature carbon monoxide adsorption characteristics of K/Co/Rh/Mo/AI2O3 catalysts are studied by chemisorption and FT-IR techniques. Most of the IR bands can be traced to those observed for Rh/AI2O3, K/Rh/Al2O3, and K/Rh(111). Several bands in the 1700-2000 cm-1 region become quite intense in these multicomponent catalysts when potassium loadings exceed 3 wt%. Significant intensity is observed only when all four elements are present with appropriate loadings. Studies with one-component precursors show: (1) the presence of Mo(0) in Mo/Al2O3 samples reduced at 673 K, (2) cobalt(+2) in octahedral positions on the alumina distinguishable from cobalt(+2) in particles of cobalt, and (3) the presence of a new band for Rh/Al2O3 at 2007 cm-1. Studies with Rh/Mo/Al2O3 suggest Mo covers mainly the surfaces of the larger particles of Rh and forms a mixed oxide layer that does not chemisorb CO. © 1991.