Synthesis and Characterization of Gold-nano Particle Supported on Na-Y and H-Y type Zeolite and Activity and Thermal Stability for CO Oxidation

Nano-gold particles were deposited on Na-Y and H-Y zeolite modified from NH4-Y type zeolite using chloroauric acid solution. The synthesized catalysts were characterized and then its activity was measured in a fix bed quartz-tubular reactor (7mm i.d.) under atmospheric pressure. In order to investigate its catalytic activities toward CO oxidation reaction, 31 ml/min of air and 0.155 ml/min of carbon monoxide were mixed and then passed through the reactor. It was found that Au/Na-Y and Au/H-Y fresh catalysts at 20°C have 100% and 5% CO conversion respectively. It was found that Au/Na-Y required an induction period in order to reach a complete activity at 20°C. The stability of catalysts was measured at 400°C for 4h that catalysts have complete conversion. The activity of the Au/Na-Y catalyst was decreased to 65% at 20°C and the activity of the Au/H-Y was increase to 15% after thermal stability test. Results of Energy Dispersive Analysis by X-rays (EDAX) before and after thermal stabilization of the Au/Na-Y catalyst were showed that Au content of these samples were3.89% and 1.76 respectively. It was found that the amount of Au content decrease after thermal stability process. Fourier Transform Infrared (FTIR) spectra were showed no changes in framework structure of zeolite during thermal stabilization process of the catalyst.

کلیدواژه ها:

Gold nano particle ، NH4Y-type zeolite ، CO oxidation ، Catalyst ، Thermal stabilization