Direct air capture (DAC) of carbon dioxide has been identified as a necessary negative emission technology to limit global temperature rise to 2 °C by 2100. With the research progress in DAC, an increasing number of adsorbents have been developed and investigated. This brings about the questions that what makes good adsorbents for DAC and how to characterize and compare them with different natures. In this paper, the performance parameters of state-of-art DAC adsorbents were investigated, and it is found that because of the varying test conditions, the comparison of some parameters appears to be difficult. Therefore, it is recommended that for each performance parameter, it is best to determine relatively uniform test methods. To this end, this paper selected five benchmark adsorbents and used a set of test methods as a demonstration. Key performance parameters of the adsorbents were measured. On this basis, by comparing the results with that in existing research, the characteristics of different types of adsorbents were summarized and suggestions for future material development were provided.

二氧化碳的直接空气捕获 (DAC) 已被确定为到 2100 年将全球温度上升限制在 2°C 的必要负排放技术。随着 DAC 的研究进展，已经开发和研究了越来越多的吸附剂。这带来了一些问题，即什么是好的 DAC 吸附剂以及如何表征和比较它们与不同性质的吸附剂。在本文中，研究了最先进的 DAC 吸附剂的性能参数，发现由于测试条​​件的变化，一些参数的比较似乎很困难。因此，建议对每个性能参数，最好确定比较统一的测试方法。为此，本文选取了五种基准吸附剂，并采用了一套测试方法作为示范。测量了吸附剂的关键性能参数。在此基础上，通过将结果与现有研究结果进行比较，总结出不同类型吸附剂的特点，为今后材料的发展提供建议。