Ir/ZrO_2催化剂对甲烷催化燃烧性能的研究

Catalytic Combustion of Methane over Ir/ZrO_2 Catalysts

采用浸渍法制备了ZrO2为载体负载Ir的催化剂(Ir/ZrO2),考察了催化剂的CH4催化燃烧性能.采用X射线衍射(XRD),拉曼光谱(Raman),X射线光电子能谱(XPS),氢气程序升温还原(H2-TPR)等技术对催化剂的结构和Ir物种的存在形式进行了表征.结果表明,Ir/ZrO2催化剂中Ir是以IrO2形式存在的,Ir/ZrO2催化剂的CH4燃烧表观活性随着Ir负载量的增加而提高,并且催化剂表现出较高的催化活性和良好的反应稳定性.在低Ir负载量(≤1%)时,CH4燃烧的转换频率(TOF)随着Ir粒子的增大而提高;然而高Ir负载量(≥1%)时,TOF随着Ir粒子的增大保持不变.

Ir catalysts supported on ZrO2 were prepared by an impregnation method,and their catalytic performance for CH4 catalytic combustion were tested.The catalyst structure and Ir species in the catalyst were characterized by X-ray diffraction（XRD）,Raman spectroscopy,X-ray photoelectron spectroscopy（XPS） and H2 temperature programmed reaction（H2-TPR） techniques.The results showed that Ir existed in the form of IrO2 in the Ir/ZrO2 catalysts.The apparent activity of Ir/ZrO2 catalysts for CH4 combustion in-creased with Ir loading,and the catalysts showed high activities as well as good stability.Turnover fre-quency（TOF） for CH4 combustion increased with Ir particle size with low Ir loading（≤1%）,however,it remained constant with high Ir loading（≥1%）.