本文报道了在超高真空下用四极质谱计来测量粉末样品热脱附谱的实验方法,并用它得列了电解银催化剂表面吸附氧以后的热脱附谱。实验表明,氧的热脱附谱峰位发生在300℃附近,且随升温速率β增大而增加。由谱峰形状的对称性和峰位随初始覆盖度增大而下降,可判断它是二级脱附,计算得到的脱附活化能为42 kcal/mol。 In this paper, the experimental method for measuring the thermal desorption spectra of powder samples by using a quadrupole mass spectrometer under ultrahigh vacuum was reported. The thermal desorption spectra of the adsorbed oxygen on the surface of electrolytic silver catalysts were also obtained. Experiments show that the peak position of thermal desorption of oxygen occurs around 300 ℃, and increases with the increase of heating rate β. From the symmetry of peak shape and the decrease of peak position with increasing initial coverage, it can be judged that it is secondary desorption. The calculated activation energy for desorption is 42 kcal / mol.