Application of Ultrasonic Vibrations in the Preparation of Ce-Zr-La/Al2O3 and Supported Pd Three-Way-Catalyst

作者：Cai Li; Wang Kang Cai; Zhao Ming; Gong Mao Chu; Chen Yao Qiang^*

来源：Acta Physico - Chimica Sinica, 2009, 25(5): 859-863.

• Pd three-way-catalyst
• Catalytic activity
• NO-TPD
• H-2-TPR
• Textural property

CeO2-ZrO2-La2O3/Al2O3 (CZLA) was prepared by pretreatment with ultrasonic vibrations and Pd three way-catalysts (TWCs) were then synthesized. Supports were characterized using Brunauer-Emmett-Teller(BET) and X-ray diffraction (XRD). Pd catalysts were characterized using NO-temperature programmed desorption (NO-TPD), H-2-temperature programmed reduction (H-2-TPR) and a catalytic activity test. The specific surface area of the uv-CZLA (CZLA with ultrasonic vibration) and the n-CZLA (CZLA without ultrasonic vibration) was 130 and 1.17 m(2).g(-1), respectively, after calcination at 900 degrees C. The uv-CZLA material had larger pores of 11.4, nm and this made it more thermally stable than the n-CZLA. uv-CZLA supports were calcined at various temperatures and showed only one Ce0.5Zr0.5SO2 phase. However, theta-Al2O3 was observed in n-CZLA after aging at 1150 degrees C for 5 h. Almost no difference in NO-TPD was found for fresh and aged Pd/uv-CZLA catalysts. Results from the H-2-TPR of the Pd/uv-CZLA catalyst showed a higher reductive peak temperature and a far larger reducing peak area than that of Pd/n-CZLA. Results of three-way reactions show that the catalyst prepared using ultrasonic vibration treatment possesses a lower light-off temperature for the removal of all three main pollutants in vehicle emissions and also a better temperature property.

• 出版日期2009-5
• 单位四川大学