Effect of Iron Addition on Bromination Reaction of Silicon

The bromination of metallurgical grade silicon (MG-Si) was investigated in a flow reactor in the presence of iron under various conditions. The reactivity of Si samples was evaluated with respect to HBr conversion and SiHBr 3 selectivity, while product purity was analyzed after hydrolyzing them to silicon dioxide (SiO 2 ). The concentration of metal elements in the product were much less than those in MG-Si. The addition of iron resulted in no significant increase in metal impurities. Rather, it resulted in an improvement of reaction kinetics in a temperature range of 380-400 ℃, probably as a result of better catalytic action in the reactant due to the substance accelerating the catalysis of iron. The activation energy for the overall bromination reaction in the presence of iron was estimated to be 129 kJ/mol.