Pd-W and Pd-Mo catalysts for NO decomposition and NO/CO reduction reactions

pd/γ-al2o3 catalysts with two different metal particle sizes were prepared from [pd(acac)2]. subsequently, the photochemical reaction of [m(co)6] (m = mo or w) in the presence of pd/γ-al2o3 was used to prepare bimetallic pd-m/γ-al2o3 catalysts. drifts ftir spectra of the catalyst surfaces prior to thermal decomposition showed unstable subcarbonyl [m(co)n] species. chemisorption and co/no adsorption results indicated a blockage of the pd active sites when the second metal was incorporated. the catalytic activity and the selectivity for the no/co reaction were higher for pd with higher particle size, but they were both inhibited when mo or w were incorporated. on the other hand, when the catalysts were tested for no decomposition, the presence of mo or w led to an increase in the catalytic activity, with optimal results observed in the presence of mo.