Kinetic Study of the Recombination Reaction of Gas Phase Pd(a1S0) with O2 from 294 to 523 K
Kinetic Study of the Recombination Reaction of Gas Phase Pd(a1S0) with O2 from 294 to 523 K
复制标题
294~523 K 气相 Pd(a1S0) 与 O2 复合反应动力学研究
DOI：
--
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
J. Plane
中科院分区：
文献类型：
--
作者：
M. L. Campbell;J. Plane
报道了在Ar缓冲溶液中，基态钯(A1S0)与氧反应的气相脱除速率常数随温度和压力的变化。利用三氟乙酸钯(II)的光解离产生钯原子，并用激光诱导荧光法进行检测。该反应依赖于压力，表明复合生成PdO2。当压力超过20Torr时，可以观察到衰减行为。量子计算表明，反应在三重态表面上进行，形成弯曲的PdO_2(3A‘ ’)，其低频弯曲模仅为129 cm~(-1)，键能D_0=95kJ·m ol~(-1)。与实验数据相吻合的RRKM理论表明，D_0应在155kJ·mol~(-1)以下，并预测在200~600K之间的速率系数为： krec，0=1.09×10~(-30)(T/300K)-2.76cm6分子~(-2)S~(-1)，krec，∞=2.52×10~(-10)exp(−69.3/T)cm~3分子~(-1)S~(-1)，fc=0.61。
The gas-phase removal rate constants for the reaction of ground-state palladium (a1S0) with oxygen in argon buffer are reported as a function of temperature and pressure. Palladium atoms were produced by the photodissociation of palladium(II) trifluoroacetate and detected by laser-induced fluorescence. The reaction is pressure dependent, indicating recombination to form PdO2. Falloff behavior is observed at pressures above about 20 Torr. Quantum calculations indicate that the reaction proceeds on a triplet surface to form bent PdO2(3A‘ ‘), which has a low frequency bending mode of only 129 cm-1 and a bond energy D0 = 95 kJ mol-1. RRKM theory, fitted to the experimental data, shows that D0 should lie below 155 kJ mol-1 and predicts the following expression for the rate coefficient from 200 to 600 K: krec,0 = 1.09 × 10-30 (T/300 K)-2.76 cm6 molecule-2 s-1, krec,∞= 2.52 × 10-10 exp(−69.3/T) cm3 molecule-1 s-1, and Fc = 0.61.