Combining Fourier Transform Infrared and Raman Spectroscopy to Characterize Kerogen Molecular Structures: Insights into Their Thermal Maturity

作者：Dun Wu, Chenglong Wang, Wenxu Liang, Xia Gao · 发表于：International Journal of Molecular Sciences · 年份：2025 · DOI：10.3390/ijms26062696 · 被引用次数：9 · 研究领域：Hydrocarbon exploration and reservoir analysis、Petroleum Processing and Analysis、Coal Properties and Utilization

This study systematically analyzed the composition of organic functional groups and changes in the carbon structure of kerogen at different stages of thermal maturity using Fourier Transform Infrared (FTIR) spectroscopy and Laser Raman spectroscopy techniques. The research selected oil shale samples from the Late Carboniferous deep coal strata in the southern part of the Huainan coalfield. Kerogen was extracted through acid treatment, pyrite removal, and heavy liquid separation processes. Utilizing FTIR and Raman spectroscopy, the study delved into the quantitative and qualitative characteristics of functional groups such as hydroxyl, carboxyl, and methyl in the kerogen, as well as the variations in the ratio between aliphatic and aromatic carbon. The research found that as thermal maturity increased, aromatic structural parameters in the kerogen significantly rose, while aliphatic structural parameters exhibited a downward trend. Specifically, FTIR spectroscopy was used to identify the characteristic absorption wavenumber ranges of different functional groups and calculate key parameters such as the aromaticity of the kerogen and the ratio of aliphatic to aromatic functional groups using relevant formulas. Meanwhile, Raman spectroscopy analysis revealed changes in the orderliness of carbon atoms and the degree of graphitization in the kerogen as a function of thermal maturity, with the intensity ratio of the G band to the D1 band (AD1/AG) emerging as an important indicator f...