EFFECT OF RHODIUM ADDITIVE ON THE REDUCTION BEHAVIOUR OF IRON OXIDE IN CARBON MONOXIDE ATMOSPHERE

2017 Malaysian Journal of Analytical Science  
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/Fe 2 O 3 samples were prepared by impregnation method and the reduction behavior of Rh/Fe 2 O 3 and pure Fe 2 O 3 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/Fe 2 O 3 give
more » ... better reducibility compared to Fe 2 O 3 with a complete reduction at 650 °C, which is 250 °C lower than Fe 2 O 3 . The TPR results indicate that the reduction of Fe 2 O 3 proceed in three steps reduction (Fe 2 O 3 → Fe 3 O 4 → FeO → Fe) with Fe 3 O 4 and FeO as intermediate states while for Rh/Fe 2 O 3 as the TPR result showed the overlapping of second and third peak (Fe 3 O 4 → 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 Fe 3 O 4 → Fe so the reduction process of Fe 2 O 3 become faster. The XRD pattern shows the diffraction peaks of Rh/Fe 2 O 3 is more intense with improved crystallinity for the characteristic peaks of Fe 2 O 3 compared to pure Fe 2 O 3 . 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 Fe 2 O 3 .
doi:10.17576/mjas-2017-2104-17 fatcat:heoutsbqdnbx7c4ydvlmzukhhq