Department of Chemistry and Polymer Science, University of Stellenbosch, Matieland, 7600, South Africa.
ChemSusChem. 2020 Jan 9;13(1):102-105. doi: 10.1002/cssc.201902990. Epub 2019 Nov 18.
Enthalpy of sorption (ΔH) is an important parameter for the design of separation processes using adsorptive materials. A pressure-ramped calorimetric method is described and tested for the direct determination of ΔH values. Combining a heatflow thermogram with a single sorption isotherm enables the determination of ΔH as a function of loading. The method is validated by studying CO sorption by the well-studied metal-organic framework Cu-HKUST over a temperature range of 288-318 K. The measured ΔH values compare well with previously reported data determined by using isosteric and calorimetric methods. The pressure-gradient differential scanning calorimetry (PGDSC) method produces reliable high-resolution results by direct measurement of the enthalpy changes during the sorption processes. Additionally, PGDSC is less labor-intensive and time-consuming than the isosteric method and offers detailed insight into how ΔH changes over a given loading range.
吸附焓（ΔH）是使用吸附材料设计分离过程的重要参数。本文描述并测试了一种压力斜坡量热法，用于直接测定ΔH 值。通过将热流热谱图与单个吸附等温线相结合，可以确定作为负载函数的 ΔH。通过研究在 288-318 K 温度范围内 CO 在经过充分研究的金属-有机骨架 Cu-HKUST 上的吸附，对该方法进行了验证。所测量的 ΔH 值与先前使用等摩尔和量热法确定的数据吻合较好。通过直接测量吸附过程中的焓变，压力梯度差示扫描量热法（PGDSC）可产生可靠的高分辨率结果。此外，与等摩尔法相比，PGDSC 劳动强度和时间消耗更小，并且可以深入了解在给定负载范围内 ΔH 如何变化。
