2-20　石炭の低温酸化における水の影響

化学構造解析

抄録

To observe oxygen functional groups generated during oxidation reaction by water (H₂¹⁷O), coal was treated at 40–80 degree C under ¹⁶O₂ atmosphere. Solid state ¹⁷O MAS NMR spectra of the heated coal were acquired by using Oldfield Echo pulse sequence. Since the ¹⁷O MAS NMR spectrum acquired by Single Pulse sequence suffered from distortion caused by ringing phenomenon, the Oldfield Echo pulse sequence was used to eliminate the spectral distortion. As a result, two kinds of oxygen functional groups generated in coal oxidized by water were observed. Furthermore, these areas of ¹⁷O NMR spectra became large as oxidation temperature was high, indicating that the amount of oxygen functional groups increased with an increase of oxidation temperature.