【摘要】 测定了10个含不同稀土Ln_0.7Sr_0.3MnO₃（Ln=La,Ce,Pr,Nd,Sm,Gd,Tb,Dy,Ho和Er）催化剂的TPD谱。从室温到1023K程序升温出现α,β,γ和θ四个脱附峰,从能量分析以及分别将473K、573K时的CO氧化转化率和TPD谱中α、β峰的峰温相关联,认为α峰（脱附峰温度为371K～431K）可能为O₂^-（吸）,该氧物种为473K时CO氧化反应的主要活性氧物种;β峰（脱附峰温度为479～538K）可能为O^-（吸）,该氧物种以α峰对应的氧物种为573K时CO氧化的主要活性氧物种;γ峰（脱附温度为921～929K）对应的氧物种可能为吸附在和锰离子连接的桥键晶格氧空位上的吸附氧物种O^2-;而θ峰（脱附温度≥1023K）对应的氧物种为体相晶格氧,若该类O^2-脱附,会使结构坦塌。更多还原

【Abstract】 TPD spectra of catalysts Ln_0.7Sr_0.3MnO₃ （Ln=La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Er） are determined. Four Peaks, α, β, γ and θ, emerge on temperature program desorption （TPD） spectra from room temperature to 1023K. According to analysis of energy and correlation between peak temperature of TPD and CO conversion%, it is believed that the α peak of oxygen species （371—431K） may be O₂^-（ad.）, which is active oxygen species for CO oxidation at 473K, the β peak of oxygen species （479—538K） may be O^-（ad.） or O^-（lattice） on surface; which is active oxygen species for CO oxidation at 573K; the γ peak of species（921—929K） may be adsorption O^2-, adsorbed on the vacancies in brige bonds linked to Mnⁿ⁺, the behaviour is similar to that of bulk lattice oxygen. The θ peak of species （≥1023K） may be bulk lattice oxygen. If the last kind of oxygen species is desorbed, the structure collapses.更多还原