Hematite promotion

Photoenhanced adsorption of SO2 occurs on goethite (Inoue et al., 1988) and on hematite (Toledano et al., 1998). Ultrafine particles of goethite promote photoreduction of adsorbed dinitrogen to ammonia (Tennakone et al., 1991). 

Examples include the oxalate (10 M) promoted dissolution of goethite, hematite and ferrihydrite over the pH range 3-5 (Fig. 12.2) in the absence of the ligand, dissolution at this pH is essentially zero (Stumm et al., 1985). 

The spherical or disk-like particles of hematite dissolved and large, octahedral crystals of magnetite precipitated. The dissolution process involved electron transfer between hydrazine and the Fe of the hematite and was promoted by complexing agents such as TEA. 

Fig. 5. The effect of germanium promotion on the activity and deactivation of hematite in the vapour phase methylation of 2-ethyl aniline by methanol.

The catalytic activity of Fe carbides, molybdenum oxynitride and oxycarbide has been evaluated for coal liquefaction and heteroatom removal of model compounds related to coal. Preliminary results show that the LP nanoparticles are active catalysts for coal liquefaction. In fact, they are more active for heteroatom removal than a molybdenum promoted sulfated hematite, even though surface characterization indicates that as introduced into the reactor they exhibit surface oxidation. 

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