Triple Function Ru Catalysts for Low-Temperature Co Oxidation, Voc Combustion and Scr-Denox

Introduction For emissions control of multicomponent exhaust gas streams, catalytic converters have to perform three functions: the catalytic oxidation of carbon monoxide to carbon dioxide, the destruction of Volatile Organic Carbon compounds (VOC’s), and NOx abatement. State-of-art catalysts for CO oxidation are based on CuMn2O4 (hopcalite), for VOC combustion on Pt/alumina, and for DeNOx either supported noble metals (Rh, Pt, Pd) or redox metals (V, Mn) are commonly employed. Extensive research has focused on the improvement of catalytic activity at low temperatures. We have applied high-throughput and combinatorial approaches to the discovery of more efficient catalysts for low temperature CO oxidation, VOC combustion and DeNOx [1-5]. The screening approach was based on a hierarchy of qualitative and semi-quantitative primary screens for the discovery of hits, and quantitative secondary screens for hit confirmation, lead optimization and scaleup. Parallel IR thermography and fast serial scanning mass spectrometry were the primary screens for CO oxidation and SCR-DeNOx, respectively, using wafer-formatted libraries of 256 catalysts with CO/O2/N2 and sulfurand water-free NH3/NO/O2/Ar model feeds. Multi-channel fixed bed reactors equipped with imaging reflection FTIR spectroscopy or GC were used for scale up as well as VOC screening using propylene/O2/N2 model feed.