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Molecular‐Level Insights into the Oxidative Degradation of Grafted Amines
Author(s) -
Ahmadalinezhad Asieh,
Tailor Ritesh,
Sayari Abdelhamid
Publication year - 2013
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201300864
Subject(s) - chemistry , adsorption , amine gas treating , degradation (telecommunications) , imine , mesoporous silica , amide , solvent , mesoporous material , organic chemistry , catalysis , telecommunications , computer science
The oxidative degradation of CO 2 adsorbents consisting of amine‐grafted pore‐expanded mesoporous MCM‐41 silica was investigated. The adsorbents were treated under flowing air at various temperatures, and the degree of deactivation was evaluated through the measurement of their CO 2 adsorption capacity prior and subsequent to exposure to air. To decipher the chemical structure of surface species upon air‐deactivation of grafted amines, a solvent extraction procedure was developed using a deuterated basic solution. The obtained solutions were analyzed by a variety of 1D and 2D NMR spectroscopy techniques, such as 29 Si, 13 C, 1 H, [ 1 H, 15 N] HMBC, [ 1 H, 13 C] HMQC, COSY and DOSY. The surface species generated by oxidative degradation of amine‐grafted silica were found to contain functional groups such as imine, amide and carboxylic groups. Several structural units were conclusively demonstrated.