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/NiAl 2 O 4 catalyst for coking-free partial oxidation of methane reaction at low temperature (450 degrees C). The catalyst was tested in a packed-bed reactor over a temperature range of 350 to 850 degrees C. The NiO-MgO/NiAl 2 O 4 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 % CH 4 conversion and varying H 2 /CO selectivities from 90 % to 70 % at 450 degrees C. A stability test was conducted at 500 degrees C for 100 h for stream on reaction conditions, resulting in 95 % CH 4 conversion, 90 % H 2 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 NiAl 2 O 4 contributed to these properties.