Iron ore catalysts for methane decomposition to make COx free hydrogen and carbon nano material

In this work, for the first time, iron ores with 91.7%-96.2% Fe2O3, 1.3%-2.3% Al2O3, 1.2%-4.5% SiO2, 1.3%-3.9% Na2O, were studied directly as bulk catalysts for methane decomposition. By hydrogen pre-reduction at 850 degrees C, Fe2O3 species on iron ores were gradually reduced into Fe3O4, FeO and then finally into Fe species. After reduction of 1.6 g of iron ore catalysts of 50 m particle size with 100 mL/min pure H-2 for 3.5 h at 850 degrees C, CMD life testing was conducted at 850 degrees C and GHSV of 3.75 L/g(cat) h and the catalyst showed a stable methane conversion for 5 h. When methane decomposition proceeded on Fe sites, Fe3C species would be formed to deposit graphite around themselves to finally form carbon nano onions. This carbon nano onions material showed excellent application for wastewater purification. All samples were fully characterized with XRF, XRD, H-2-TPR, TEM and Raman. (C) 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.