Dry reforming of methane with a new catalyst derived from a negative value mining residue spinellized with nickel

- A novel Ni-based catalysts from a negative value mining residue.
- Improved solid state reaction for spinel preparation.
- New catalyst use in dry reforming of methane.
- Role of catalyst composition in avoiding carbon deposition.

Using an improved solid-state reaction protocol, a new nickel catalyst was prepared from an ilmenite metallurgical residue consisting of an upgraded slag oxide (UGSO). Dry reforming of methane (CH4) was chosen as the application to test the Ni-UGSO catalytic performance. The reforming reactions were conducted at 800-840 °C and atmospheric pressure using mole CO2/CH4 ≈ 1 and a space velocity 2900 mL/h gcat. The catalytic performance was evaluated by means of CH4 and CO2 conversions and mole H2/CO in the produced syngas, and long-term stability as well. The results revealed that Ni-UGSO exhibits higher CH4 and CO2 conversions and H2 yields compared both to the original UGSO and to a spinel ferrite (NiFe2O4) catalyst. Moreover, these high catalytic performances are equivalent or superior to those described in the literature. Specific interactions between the active metal Ni and the various UGSO components (MgO, CaO, MnO basic character and other elements such as promoters) have been advanced to explain the best catalytic performance achieved by this upgraded catalytic material which, furthermore, exhibited no measurable carbon deposition. Both fresh and spent catalysts were thoroughly characterized by TPR, TG-MS, XRD, SEM, EDX, BET and XPS to reinforce interpretation of our findings.

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