NiO–MgAl2O4 systems for dry reforming of methane: Effect of the combustion synthesis route in the catalysts properties

Ni-based catalysts supported on MgAl2O4 were synthesized by microwave-assisted combustion method, by varying the content of fuel and the route of addition of the active phase (one-pot or incipient impregnation). The catalysts were characterized by in-situ and ex-situ X-ray diffraction, N2 physisorption, temperature programmed reduction and thermogravimetric analysis. In-situ X-ray diffraction analysis (using synchrotron radiation) was used to identify and evaluate the nickel particle size after catalyst activation. The catalytic tests (dry reforming) were carried out at 800 °C for 12 h (GHSV = 72 Lh−1g −1) for both catalysts. It was observed that both the route of addition of the active phase and the amount of urea promoted different effects on the catalytic properties. The results indicate that the combination of the one-pot method with high urea content produces catalysts with high catalytic activity without the need of subsequent calcination. [Display omitted] •The amount of fuel during the synthesis by microwave-assisted combustion influenced the surface area and pore volumes.•Catalysts prepared with low amount of fuel showed good performance and stability against the RSM process.•Catalyst prepared by the one-pot method (NiMA-OHC) showed high reactivity, low cost and only a single preparation step.•Catalysts showed low levels of carbon deposition, even in tests with high GHSV.