Mechanism of CO₂ adsorption on amine loaded SBA-15 sorbents with varying amine coverage has been assessed using thermogravimetric analysis (TGA) and in-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). TGA study showed that sorbent adsorption capacities increased by 122–153% with CO₂ concentrations (5–80%) in the gas at 50/75 °C. The DRIFTS studies indicate that low amine loaded sorbents exhibit higher uptakes with an increase in CO₂ concentrations which is attributed to the mode of CO₂ adsorption i.e. 1:1 CO₂ to amine forming carbamic acid. At higher amine loadings CO₂ is adsorbed following the 1:2 CO₂ to amine forming carbamate-ammonium ions pair resulting in lower adsorption capacities per amine site. The studies also showed an increase in carbamic acid formation with pressure from 100 to 500 kPa at low amine loadings and both carbamic acid and carbamates at higher amine loadings. The paper provides insights into the mechanistic understanding of CO₂ adsorption behaviour of the varyingly covered amines on the SBA-15 support with a change in concentration and pressure of CO₂. The current work presents the conditions to alter the CO₂ adsorption mechanism on amine sites with potential application in CO₂ conversion to chemicals.

使用热重分析（TGA）和原位漫反射红外傅里叶变换光谱（DRIFTS）评估了在胺负载量不同的胺负载SBA-15吸附剂上CO ₂吸附的机理。TGA研究表明，在50/75 °C的气体中，CO ₂浓度（5–80％）时，吸附剂的吸附能力提高了122–153％。DRIFTS研究表明，低胺负载吸附剂随着CO ₂浓度的增加而显示出更高的吸收率，这归因于CO ₂吸附的模式，即1：1的CO ₂对形成胺的氨基甲酸的吸附。在较高的胺负载量下，CO ₂会按照1：2的CO ₂吸附对胺形成氨基甲酸酯-铵离子对，导致每个胺位点的吸附能力降低。研究还表明，在低胺含量下，氨基甲酸的形成从100 kPa增加到500 kPa，而在高胺含量下，氨基甲酸和氨基甲酸酯的含量增加。本文提供了深入了解的CO的机制理解₂上与浓度的变化和压力CO的SBA-15支持变化地覆盖胺的吸附行为₂。当前的工作提出了改变胺位点上的CO ₂吸附机理的条件，并潜在地应用于将CO ₂转化为化学物质中。