Promoters on the Reduction Process

While the reduction of unpromoted Fe proceeds at a relatively low temperature and the reduced sample has a low porosity, the presence of the promoters leads to a much higher porosity for the reduced samples. However, the presence of the promoters also has a profound influence on the kinetics of the reduction process. 

A1 decreases the rate of reduction for (Fe,Al)-oxide samples [130], in particular in wet atmospheres [135,136]. For AI2O3 supported catalyst models, the partial dissolution of A1 during impregnation leads to a more difficult reduction [137]. 

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