A STUDY OF THE IRON/SODALITE CATALYST FOR THE PARTIAL OXIDATION OF METHANE TO METHANOL

摘要

The synthesis, characterisation and reactivity of an iron/sodalite catalyst for the partial oxidation of methane to methanol are described and discussed. In a limited temperature range, ca. 410°C, and at 34 bar total pressure, the selectivity to methanol is found to be similar to that observed for the empty silica glass reactor. Before reaction, powder X-ray diffraction and 57Fe Mossbauer spectroscopy confirm the presence of Fe(III) in the sodalite framework. After reaction the structure is more complex, as revealed by 57Fe Mossbauer spectroscopy and transmission electron microscopy, and both Fe(II) and Fe(III) are present. In particular, small particles of Fe2O3, < l^im in size are also present in the used catalyst. The nature of the active site is discussed in terms of an Fe(II)/Fe(III) couple involving both framework and non-framework iron.