Do Kyoung Kim

Wide Temperature Window in the Catalytic Activity of Novel Pt/ZSM-5 Prepared by a Sublimation Method for Selective Catalytic Reduction of NO

The removal of nitric oxide from the exhaust gas of lean-burn engines is not fully commercialized since the current catalyst technology cannot meet the strict future emission regulations. Although ZSM-5 ion-exchanged with Pt (Pt/ZSM-5) has been considered as a promising catalyst due to its superior low-temperature activity, it has the drawback of a narrow “temperature window” for activity, i.e. an abrupt decrease in the activity above 300 °C. This paper reports on the preparation of novel Pt/ZSM-5 by subliming Pt(CO)2Cl2 into H-ZSM-5 at 220 °C, resulting in excellent activity within a wide temperature window between 230 and 500 °C. Pre-treatment of this Pt/ZSM-5 can change the width of the temperature window. Moreover, H2O plays a role as a promoter and SO2 reversibly reduces the activity by less than 20%.

Discovery of New Heterogeneous Catalysts for the Selective Oxidation of Propane to Acrolein

Combinatorial synthesis and screening technique have been applied to investigate the catalytic activity and selectivity of ternary and quaternary mixed-metal oxide catalysts for the selective oxidation of propane. The catalyst libraries were prepared via a modified sol-gel method using a synthesis robot and library design software, and examined for the catalytic activities in a simple high-throughput reactor system connected to a mass spectrometer for product analysis. Ternary Mo-Cr-Te, V-Cr-Sb, and Mo-V-Cr catalysts have been selected for potential candidate by composition spread approach. In a next generation composition spread library, the composition space of these three ternary compositions was sampled. Screening of this 198-member library provided substantial evidence that each ternary system has its own optimum composition where acrolein formation is highest. In addition, the composition space of the quaternary reference system Mo-V-Te-Nb mixed-oxides has also been prepared and sampled.