根据容积法原理,利用赛特拉姆气体吸附仪测量超临界温度下氢气在活性炭上的吸附等温线,并通过Gibbs关于吸附的定义,讨论了死体积的标定精度方法对计算吸附量所产生的影响.结果表明,死体积标定的误差对低压下吸附量的计算影响不大,但对高压下吸附量的计算影响明显;活性炭比表面积越大,同一温度下出现最大过剩吸附量所需要的平衡压力越高.
According to the principle of volumetric method for adsorption measure, hydrogen adsorp- tion isotherm at 77 K on SAC-02 activated carbon was measured by using Setaram Pro ELSE. Adsorp- tion data was analyzed by the definition of adsorption described by Gibbs, and the in influence of the dead volume of the adsorption system on the accuracy of the isotherm was further discussed. Results show that the method of the volume calibration has little impact to the adsorption isotherm at low pressure region, but the influence will be enhanced while the equilibrium pressure gets higher. Con- clusions were drawn that, at the same temperature, a larger pressure corresponding to the maximum point of the excess adsorption isotherm was needed while the activated carbon had a higher specific surface area.