CO气体分子在金属氧化物SrO(001)表面吸附和脱附机理

研究了高纯度金属氧化物SrO粉末表面吸附C¹⁸O后在程序升温热脱附过程中的脱附反应规律,讨论了CO气体分子在SrO(100)表面吸附和脱附之间的关系及机理.SrO吸附C¹⁸O后,在升温过程中可通过氧的同位素交换生成C¹⁶O而脱附,同时伴随少量C¹⁸O的直接脱附,并与C¹⁶O具有相近的脱附活化能.C¹⁶O的脱附量随C¹⁸O气体暴露量增加而增加,但当气体覆盖度超过一定值后,脱附量趋于定值.脱附峰值温度随气体暴露量的增加而下降.

Mechanism of Adsorption and Desorption of CO on SrO(001) Surface

The desorption behaviors of C 18O on the particle surface of SrO(001) were investigated by the method of Temperature Programmed Desorption (TPD). The mechanism responsible for desorption process and the relationship between adsorption and desorption were discussed. C 16O formed due to the exchange of oxygen isotopes and escaped from the surface of SrO particles during heating the particles pretreated with the absorption of C 18O gas. A small amount of C 18O also desorbed from the particle surface and the activation energy of C 18O desorption was approximate to that of C 16O desorption. With the increasing of the exposure amount of C 18O gas, the desorption amount of C 16O was increased and the peak desorption temperature was decreased. However, the desorption amount of C 16O tended to become constant when the surface coverage of C 18O gas was higher than a certain value.