Nano-crystalline NiO-MgO/NiAl2O4 catalyst for coking free low temperature partial oxidation of methane

Abstract

Here, we report an ultra-small-sized nano-crystalline NiO-MgO/NiAl2O4 catalyst for coking-free partial oxidation of methane reaction at low temperature (450 °C). The catalyst was tested in a packed-bed reactor over a temperature range of 350 to 850 °C. The NiO-MgO/NiAl2O4 catalyst was optimized for calcination temperature and nickel content. The best-optimized sample was then tested for different gas hourly space velocities (GHSVs), resulting in 99 % CH4 conversion and varying H2/CO selectivities from 90 % to 70 % at 450 °C. A stability test was conducted at 500 °C for 100 h for stream on reaction conditions, resulting in 95 % CH4 conversion, 90 % H2 selectivity, and 60 % CO selectivity without any significant deactivation. The excellent catalytic activity and stable performance were attributed to the ultra-small size and nanocrystalline structure of NiO-MgO, as well as the presence of lattice oxygen reservoirs. Additionally, the synergistic interaction between the NiO-MgO solid solution and the support NiAl2O4 contributed to these properties.