Measurement Of Temperatures During Plasma Treatment Of Catalysts

Plasma is the forth phase of matter in the world, and it has been applied inindustry widely. Our group has preciously succeeded in preparing high-activitycatalyst using cold plasma, due to the promotion of contained electrons, ions andradicals. The main purpose of this paper is to measure the temperature parameter likegas temperature and electron temperature during the preparation of catalysts, so wecan study the relative mechanism of catalysts. The detailed research includes toanalyze the emission spectrum of plasma using AVS-MC2000 spectrometer, and thento calculate the electron temperature of plasma according the data obtained; tomeasure the gas temperature of plasma using IR camera. Usually, moved or stableplasma striations are found during the preparation, so we use digital camera to showthe variety of plasma striations. Simultaneously, IR camera and AVS-MC2000spectrometer are employed to show the gas temperature and the electron temperatureof plasma striations.The main factors on electron temperature during preparing catalyst in plasma arepresent as followed.1. The support of catalysts: the electron temperature of Pd catalysts is usuallydifferent with the supports. When TiO2 is selected as the support, theelectron temperature with Pd/TiO2 is much higher than others.2. The loading of Pd: take example for HZSM-5 zeolite, the electron temperatureincreases from 10.52×104K to 12.19×104K as the Pd loading from 1% to 5%.3. The presence of water vapour: the electron temperature can increasefrom 10.6×104K to 13.0×104K at the presence of water vapour during thecatalyst preparation.Furthermore, the variety of striation and the relative temperature parameter areemphasized. It is found that the electron temperature at bright layer is much higherthan that of dark layer, and the electron temperature at the anode is the brightest andthat of at the cathode is the lowest. At last, we also use IR camera to study the gastemperature of plasma striations. It is found that the gas temperature of it doesn'tpresent the periodic variety just like the electron temperature. It becomes higher andhigher from the anode to the cathode.