TPD-质谱研究稀土氧化镨晶格氧及其与H_2和CO的反应性能  

DESORPTION AND REACTIVITY OF LATTICE OXYGEN SPECIES IN PRASEODYMIUM OXIDE STUDIED BY TPD-MASS SPECTROSCOPY

作　　者：应品良[1] 李灿[1] 辛勤[1] 

机构地区：[1]中国科学院大连化学物理研究所催化基础国家重点实验室,大连116023

出　　处：《Chinese Journal of Catalysis》1993年第6期488-492,共5页催化学报（英文）

基　　金：国家自然科学基金(青年基金)

摘　　要：稀土氧化物具有一定的催化氧化特性.Sm_2O_3和调变后的Pr_6O_(11)被认为是有希望的甲烷氧化偶联催化剂.Gaffneg等报导了氧化镨的甲烷氧化偶联活性、尤其以Na为助剂时其活性和选择性又提高了许多,所提出的机理认为是氧化镨的Redox性质起着很重要的作用.Poirier等发现镨的价态变化对甲烷氧化偶联反应影响较大。Desorption and reactivity of lattice oxygen in Pr6O11 catalyst have been studied by temperature-programmed desorption(TPD)-mass spectros-copy in temperature range of 25-800℃. There appear three TPD peaks of oxygen (m/e= 32) at 425.540 and ~850℃ which are due to three kinds of lattice oxygen in Pr6O11 denoted as α,β,and y lattice oxygen respectively. The α,β oxygen could be removed by outgassing at temperature higher than 600℃, but could be rapidly recovered under O2 atmosphere even at 300℃. Both the α and β oxygen show high reactivity toward CO and H2 around 350℃, whereas tha γ oxygen is inert below 500℃. The perfect mobility and reversibility of the lattice oxygen in Pr6O11 suggest that the oxide will be a candidate catalyst for a reaction involving redox mechanism.

关 键 词：氧化镨 晶格氧 一氧化碳 氢 

分 类 号：O614.334[理学—无机化学]