Effect of metal amount on the catalytic performance of Ni-Al2O3 catalyst for the Tri-reforming of methane

Mesoporous Ni-Al2O3 catalysts with Ni weight (%) 5 to 15 were synthesized, characterized, and tested for tri-reforming of methane (TRM). The characterization results reveal that the metal loading influences the metal-support interaction of the catalysts. Furthermore, the choice of reduction temperature affected the dispersion of metallic-Ni. It is advantageous to reduce these catalysts at their respective Tmax temperatures, which are obtained from H2-TPR studies. At these conditions, the dispersion was maximum. For TRM at 600 degrees C, the conversions and yields increased with an increase in Ni loading, and carbon was not detected. Increasing the metal loading from 5 wt% to 15 wt% increased the CH4 conversion from 70.5 to 82.4% and CO2 conversion from 10.2 to 19.7%. In contrast, the H2/CO ratio decreased from 3.8 to 3.2. The conversions and yields during TRM were relatively constant with time-on-stream and were highest for 15Ni-Al. Furthermore, H2/CO ratio was >3, and minimal change in dispersion was observed post-reaction for this catalyst. Thus, the active metal loading and the reduction temperature required are important parameters that need to be considered while designing a suitable catalyst for TRM.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.