Novel Rapid Screening of Basic Immobilized Amine Sorbent/Catalyst Water Stability by a UV/Vis/Cu2+ Technique

Time‐consuming thermogravimetric analysis (TGA) decomposition study is a typical practice to assess the stability of fresh and water‐treated basic immobilized amine sorbents (BIAS)/catalysts. This work presents a faster and more precise spectroscopic UV/Vis/Cu2+ sorbent screening technique that quantifies aqueous amines washed from the BIAS by using UV‐active amine/Cu2+ complexes. Six BIAS‐based catalysts, containing different amine species and a crosslinker within silica, were treated with ultrapure water and then analyzed for their CO2 capture performance and amine leach resistance/stability by using TGA (catalysts, approximately 4 h) and UV/Vis/Cu2+ techniques (wash solution, few minutes). A comparative analysis revealed that directly quantifying washed amines with UV/Vis/Cu2+ is 9–127 times more precise than indirect testing of the sorbents by TGA. Similar trends in the H2O stability profiles of the catalysts [organic content retained values (OCR)] were reported by both analysis methods, allowing UV/Vis/Cu2+ to replace TGA for quantifying unstable leached amines. The UV/Vis/Cu2+ OCR results could be used to predict the CO2‐capture stability profile of the sorbents, confirming the reliability of this technique to rapidly screen catalyst stability and performance. Have your cake and eat it too: Lengthy thermal gravimetric analysis for sorbent decomposition studies (ca. 4 h) can be replaced by a rapid UV/Vis/Cu2+ spectroscopy method (few minutes) to assess the leach resistance of basic immobilized amine sorbents/catalysts. This novel technique not only saves time but is more precise in assessing catalyst stability and predicting their performance.