Research On The Development Of A Cataluminescence-based Method For Rapid Screening Of De-NO_x

Removal of nitrogen oxides in vehicle exhaust under lean-burn conditions is one ofthe most challenging issues to address in modern automobile industry andenvironmental catalysis field. The bottleneck of the development of this field is the lackof a technique for rapid evaluation and effective screening of catalysts as well assynthesis of a huge amount of catalysts using combinatorial chemistry. In this paperusing the cataluminescence method we systematically investigated de-NO_xcatalystsdoped with multiple multi-valent metal elements. It was found that there was goodcorrelation between the chemiluminescence intensity of NO_xand its conversion within acertain temperature range. This work extended the study of chemiluminescence atnanomaterial surfaces from traditional oxidative systems to reductive systems as well asfrom simple binary catalytic reactions to the multivariate catalytic reactions, thusenriched for this specific research field. Meanwhile, it also layed the foundation forfurther realization of simple high-throughput screening of de-NO_xcatalysts. The contentof this study included:Two sets of M-BaO/Al₂O₃and M-CeO₂/TiO₂catalysts doped with differentmulti-valent elements were designed. The chemiluminescence behavior of smallmolecules such as propylene for the catalytic reduction of NO_xwas studied. It wasfound that there was clear differences among the intensities of chemiluminescencearising from the catalytic reduction of NO_xby using different catalysts. The possiblemechanism for chemiluminescence was also discussed.A micro-reactor was used as the evaluation system to study the activities of de-NO_xcatalysts at different temperatures, and the relationship between the conversion of NO_xand the temperature was derived.We observed significant correlation between the intensity of chemiluminiscencefrom the material surface and the conversion of NO_xwithin a certain temperature range.It was also proved that more active catalysts generate chemiluminescence of higherintensity.