Effect of the Calcination Temperature of LaNiO₃ on the Structural Properties and Reaction Performance of Catalysts in the Steam Reforming of Methane

The steam reforming of methane (SRM) reaction is a significant process for efficient syngas generation and for promising distributed hydrogen production. In this work, a series of LaNiO3 oxides were prepared using the Pechini method, calcined from 600 degrees C to 900 degrees C and tested for the SRM reaction. Fresh, reduced, and used samples were characterized using STA-MS-FTIR, in situ and ex situ XRD, N-2 physical adsorption, H-2-TPR, TEM, TPO, and Raman. The results show that LaNiO3 begins to crystallize at about 550 degrees C, and the increase in calcination temperature results in the following differences in the properties of the LaNiO3 samples: larger LaNiO3 grains, smaller specific surface area, higher reduction temperature, smaller Ni-0 grains reduced from the bulk phase, and stronger metal-support interaction. The maximum CH4 conversion could be achieved over LaNiO3 calcinated at 800 degrees C. In addition, the effect of steam-to-carbon ratio (S/C) on the performance of the SRM reaction was studied, and a S/C of 1.5 was found to be optimal for CH4 conversion. Too strong a metal-support interaction and too much unreacted steam causes a loss of catalytic activity. Finally, it was also proved using TPO and Raman that an increase in calcination temperature improves the carbon deposition resistance of the catalyst.