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利用程序升温脱附(TPD)和差分红外光谱方法研究了CO在Pt/Al_2O_3上的吸附和脱附。发现CO在Pt/A1_2O_3上的TPD谱存在一系列的极大值,由TPD气相产物的组成分析证明除了CO外,尚有CO_2。从差分红外光谱研究发现CO在Pt/Al_2O_3上被吸附时,随温度升高发生歧化反应,生成的CO_2同Al_2O_3表面形成一系列的羧基、羧化物、碳酸盐吸附态,它们的热稳定性不同,热脱附时产生的CO_2则是由这些吸附态脱附而形成的。TPD图谱中的一系列的极大值同这些吸附态的脱附有关。
Adsorption and desorption of CO on Pt / Al_2O_3 were investigated by temperature programmed desorption (TPD) and differential infrared spectroscopy. It is found that there is a series of maxima in the TPD spectrum of CO on Pt / A1_2O_3. The composition analysis of the TPD vapor phase products shows that there is CO_2 in addition to CO. From differential infrared spectroscopy, it was found that when CO was adsorbed on Pt / Al 2 O 3, the disproportionation reaction took place with the increase of temperature. A series of carboxyl, carboxylate and carbonate adsorbed states were formed on the surface of CO 2 and Al 2 O 3, and their thermal stability In contrast, CO 2 generated during thermal desorption is formed by the desorption of these adsorbed species. A series of maxima in the TPD map are related to the desorption of these adsorbed states.