SYNTHESIS, ACTIVITY AND THERMAL STABILITY OF GOLD NANOPARTICLE ON MODIFIED NH4-Y TYPE ZEOLITE FOR COOXIDATION

Abstract

Gold nanoparticle is the active catalyst for CO oxidation at low temperature. This feature of gold base catalysts is suitable to overcome the problem of cold-start problem of automobile exhaust TWC converters. In this study gold nanoparticle were deposited on modified NH₄-Y type zeolite. The activity of synthesized catalyst was measured in a fixed-bed quartz-tubular reactor (7mm i.d.) under atmospheric pressure. In order to investigate the catalytic activities toward CO oxidation reaction, 31mL/min of air and 0.155mL/min of carbon monoxide were mixed and then passed through the reactor. It was found that activity of Au/Y catalyst was 100% at 20^°C. The thermal stability of Au/Y catalyst was measured at 400^°C for 4h. The activity of the catalyst was decreased to 65% at 20^°C after thermal stability test. Results of Energy Dispersive Analysis by X-rays before and after thermal stability have showed that Au content of these samples were 3.89% and 1.76, respectively. It was found that the amount of Au content decreased after thermal stability process. Fourier Transform Infrared (FT-IR) spectra showed no changes in framework structure of zeolite during thermal stabilization process of the catalyst.