Highly Active Palladium Nanocatalysts for Low-Temperature Carbon Monoxide Oxidation

Abstract

The noble metal catalysts are most commonly considered to be used in an automobile as a catalytic converter. Palladium (Pd) is a highly active catalyst for carbon monoxide (CO) oxidation in platinum group metals. It is very active for low-temperature CO oxidation if dispersed on suitable metal oxides and composite oxides. The oxidized Pd metal nanocatalyst has been applied more actively than the completely reduced particles. The performance of Pd oxide nanocatalysts strongly depends upon the surface structure, number of active sites and various Pd–O interactions. Palladium is an ideal catalyst not only for the automobile industry through cross-coupling reactions but also for low-temperature catalytic oxidation of CO. The Pd metal is more resistant for sulfur and potassium poisoning, and they are chemically sensitive and degraded rapidly in the presence of fuel impurities. The higher activity of Pd nanocatalyst was attributed to the small particle size and higher dispersion over Pd support. The chemisorptions of CO on Pd catalysts were studied in this review. The results obtained from this study will provide the scientific basis for the future design of Pd-based oxidation catalysts.