REDUCTION AND REOXIDATION OF NONTRONITE: HOW WAS MAXIMAL REDUCTION ACHIEVED IN 1986-87

摘要

Iron in the octahedral sheets of layer silicates has been reduced from Fe(III) to Fe(II) using a number of different methods and reducing agents. The level of Fe(II) achieved in the clay structure cannot be predicted. For example, hydrazine and dithionite have approximately the same electrode reduction potential; however, dithionite is a more effective reducing agent. It is the only inorganic agent tested thus far that can reduce virtually all structural Fe under ambient conditions (Stucki et al., 2002). Nontronite was suspended in citrate-bicarbonate buffer solution in an inert-atmosphere reaction vessel.