Novel Rapid Screening of Basic Immobilized Amine Sorbent/Catalyst Water Stability by a UV/Vis/Cu 2+ 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/Cu sorbent screening technique that quantifies aqueous amines washed from the BIAS by using UV-active amine/Cu complexes. Six BIAS-based catalysts, containing different amine species and a crosslinker within silica, were treated with ultrapure water and then analyzed for their CO capture performance and amine leach resistance/stability by using TGA (catalysts, approximately 4 h) and UV/Vis/Cu techniques (wash solution, few minutes). A comparative analysis revealed that directly quantifying washed amines with UV/Vis/Cu is 9-127 times more precise than indirect testing of the sorbents by TGA. Similar trends in the H O stability profiles of the catalysts [organic content retained values (OCR)] were reported by both analysis methods, allowing UV/Vis/Cu to replace TGA for quantifying unstable leached amines. The UV/Vis/Cu OCR results could be used to predict the CO -capture stability profile of the sorbents, confirming the reliability of this technique to rapidly screen catalyst stability and performance.