Why Hematite is more reactive than Aluminium oxide despite having same structure

• The difference lies in the very• different surface structure of

hydrated hematite [1 ] relative to hydrated corundum [2 ].

• Hematite has two surface structural domains, one dominated by oxygens singly coordinated by Fe3+ , which are very reactive, and one dominated by oxygens doubly coordinated by Fe3+ , which are relatively unreactive (Fig. 2 ).

• corundum has only oxygens doubly coordinated by Al3+ at its surface (Fig. 3 ).

Trainor, T et al