Effect of rhodium additive on the reduction behaviour of iron oxide in carbon monoxide atmosphere [Kesan penambahan rodium terhadap tindak balas penurunan ferum oksida di dalam atmosfera karbon monoksida]

This study was carry out to investigate the effect of 3% rhodium on the reduction behaviour of iron oxide by (10%, v/v) carbon monoxide in nitrogen as a reductant. The Rh/Fe2O3 samples were prepared by impregnation method and the reduction behavior of Rh/Fe2O3 and pure Fe2O3 were investigated by using temperature programmed reduction (TPR). The prepared samples and the reduced phases were characterized by X-ray diffraction spectroscopy (XRD). The results indicate that Rh/Fe2O3 give a better reducibility compared to Fe2O3 with a complete reduction at 650 �C, which is 250 �C lower than Fe2O3. The TPR results indicate that the reduction of Fe2O3 proceed in three steps reduction (Fe2O3 ? Fe3O4 ? FeO ? Fe) with Fe3O4 and FeO as intermediate states while for Rh/Fe2O3 as the TPR result showed the overlapping of second and third peak (Fe3O4 ? FeO and FeO ? Fe) at higher temperature. Addition of Rh may possibly reduce the formation of stable FeO that stable at higher temperature by accelerates the direct reduction of Fe3O4? Fe so the reduction process of Fe2O3 become faster. The XRD pattern shows the diffraction peaks of Rh/Fe2O3 is more intense with improved crystallinity for the characteristic peaks of Fe2O3 compared to pure Fe2O3. No visible sign of rhodium particles peaks in the XRD spectrum that indicates the Rh particles loaded onto the iron oxide are well dispersed. The well dispersed Rh onto the iron oxide and the ability to reduce the sintering effect to the iron oxide also has been confirmed by FESEM. The study shows that addition of Rh gives a better reducibility of iron oxide is also due to the ability of Rh to interact with CO as confirmed by the thermodynamic data with higher surface area compared to Fe2O3. � 2017, Malaysian Society of Analytical Sciences. All rights reserved.