Amine functional adsorbents for CO₂ capture have attracted increasing attention as a possible alternative to aqueous amine. Temperature has been proven to be an important parameter that affects the CO₂ capture performance, but previous studies often yielded different optimal temperature ranges during texting and lacked multiple evaluation indicators for adsorption performance. In this study, we prepared silica modified with different loadings (10–55%) and molecular weights (600–25000 Da) of polyethyleneimine (PEI) to compare the adsorption performance under a wide temperature range (30–120 °C), which covered the temperature requirements in most applications of CO₂ capture and separation. To evaluate these adsorbents comparatively, CO₂ adsorption capacity, CO₂ adsorption kinetics, thermal stability and cyclic adsorption-desorption stability were determined. In general, the adsorbents with higher PEI loadings and molecular weights, such as 45–55 wt.% loadings or 1200–25000 Da molecular weights, were more suitable for CO₂ capture at relatively high temperatures, such as 90–120 °C. However, the performance of these adsorbents was not as good as several other adsorbents with lower PEI loadings or molecular weights for application at lower temperature, such as in CO₂ capture at ambient temperature. In addition, the essential reasons for the influence of temperature were also investigated based on the inherent properties of the adsorbents. The suppression effect and the promotion effect were proposed to explain why the optimum temperature ranges of the adsorbents were so different.

作为胺水溶液的可能替代品，用于捕获CO _2的胺功能吸附剂已引起越来越多的关注。温度已被证明是影响CO ₂捕集性能的重要参数，但是以前的研究经常在发短信期间得出不同的最佳温度范围，并且缺乏用于吸附性能的多个评估指标。在本研究中，我们制备了改性后的聚乙烯亚胺（PEI）负载量（10–55％）和分子量（600–25000 Da）改性的二氧化硅，以比较在宽温度范围（30–120°C）下的吸附性能。涵盖了大多数CO ₂捕集和分离应用中的温度要求。为了比较评估这些吸附剂，CO ₂测定了其吸附容量，CO ₂吸附动力学，热稳定性和循环吸附-解吸稳定性。通常，具有较高PEI负载量和分子量（例如45–55 wt。％负载量或1200–25000 Da分子量）的吸附剂更适合在相对较高的温度（例如90–120°C）下捕获CO ₂。但是，这些吸附剂的性能不如在较低温度下（例如在CO _2中）使用的具有较低PEI负载量或分子量的其他几种吸附剂好。在环境温度下捕获。另外，还基于吸附剂的固有性质研究了影响温度的基本原因。提出了抑制作用和促进作用，以解释为什么吸附剂的最佳温度范围如此不同。