Stabilization of Ni, Fe, and Co nanoparticles through modified Stöber method to obtain excellent catalytic performance: Preparation, characterization, and catalytic activity for methane decomposition

Nanoparticle formation from their respective precursors through bottom-up method is a very fascinating practice in nanotechnology. This research contribution discusses two promising bottom-up methods: (i) controlled precipitation of Ni, Fe, and Co nanoparticles and reinforcement with silicate through modified Stöber method and (ii) chemical vapor deposition of nanocarbon from methane. Experimental results reveal that metal oxide particles were formed as single-crystal nanoparticles after silicate addition and exhibited catalytic activity enhancing features, such as low particle size and high surface area and porosity. The single-point surface area increased from 62.22 m²/g to 91.50 m²/g, 35.13 m²/g to 97.31 m²/g, and 14.29 m²/g to 48.96 m²/g for n-NiO, n-FeO, and n-CoO nanoparticles, respectively, after silicate incorporation. Preliminary catalytic activity was also analyzed in a fixed-bed pilot plant. n-NiO/SiO₂ nanoparticles were found to be the most efficient catalyst for thermocatalytic methane decomposition and generated 57.28% hydrogen at 730 °C. Physical and chemical characteristics of the fabricated nanocatalysts were determined using N₂ adsorption-desorption measurement (Brunauer-Emmett-Teller method), X-ray diffraction (XRD), transmission electron microscopy (TEM), hydrogen temperature-programmed reduction (H₂-TPR), and field-emission scanning electron microscopy (FESEM) analyses. Produced nano-carbon was inspected with TEM, FESEM and XRD.