CO在YBa2Cu3Ox薄膜上吸附与加氢的研究

ＹＢａ２Ｃｕ３Ｏｘ（ｘ＝６－７）薄膜被合成在ＹＳＺ基底上，用ＦＴＩＲ，ＸＰＳ，ＸＲＤ等手段原位研究ＣＯ在薄膜上的吸附及加氢行为。ＣＯ吸附在Ｃｕ位置上，与ＹＢＣＯ体相中的Ｏ作用，生成表面ＣＯ２或－ＣＯＯ基团，导致ＹＢＣＯ中生产氧空位，使ＹＢＣＯ发生昌型转变，Ｃｕ＾２＋被还原为Ｃｕ＾＋或Ｃｕ＾０．ＹＢＣＯ中的氧空位有利于ＣＯ、ＣＯ２及Ｈ２的吸附。ＣＯ、ＣＯ２在ＹＢＣＯ膜上的加氢产物为ＣＨ３ＯＨ、ＣＨ３

CO Adsorption and Hydrogenation on Crystalline YBa_2Cu_3O_x Thin Films

YBa2Cu3Ox(YBCO, x=6-7) thin films have been prepared on the YSZ substrate and studied for CO adsorption and hydrogenation by using XPS, XRD, and in-situ FTIR. The results showed that CO adsorption occured at Cu sites and react with the oxygen species in YBCO, resulting in the formation of adsorbed CO2 or -COO bonding species and oxygen vacancies in YBCO,therefore, the Cu2 ions of YBCO are reduced to Cu or Cu0, and the orthorhombic structure of YBCO is transformed to the tetragonal phase. The oxygen vacancies are in favor of adsorption of CO, CO2, and H2. The main products of CO, CO2 hydrogenation are found to be CH3OH,CH3OCH3 and a trace of CH4, and the reaction intermediates might be aldehyde, formate and methoxy radical.