Governance of the porosity and of the methane decomposition activity sustainability of NiO/SiO2 nanocatalysts by changing the synthesis parameters in the modified Stöber method

Nanoscience and nanotechnology present ubiquitous possibilities in almost any scientific field because of property enhancement occurring in nanoparticles with unique size and shape. The physicochemical characteristics of nanoparticles play an imperative role in their prospective applications. This article reports an in-depth study on the variance of the physicochemical characteristics, the methane decomposition activity, and the sustainability of nano-NiO/SiO2 (n-NiO/SiO2) catalysts with different preparation parameters. The influence of nickel/silicate ratio, octadecyltrimethoxysilane (C18TMS)/tetraethylorthosilicate (TEOS) ratio, and of different solvents was investigated. The characteristic features of the prepared catalysts were inspected using N2 adsorption-desorption measurements, X-ray diffraction, hydrogen temperature-programmed reduction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, and methane cracking catalytic activity in a fixed bed reactor. Methane decomposition activity was evaluated by measuring the instantaneous hydrogen production (vol %) and carbon yield (%) at the end of the examination. The results showed that C18TMS has extensively improved the microporosity of the material, hence resulting in the improvement of the catalytic performance. The microporosity of the n-NiO/SiO2 catalyst has increased from 10.7% to 26.8% when the quantity of C18TMS was increased from 0 to 1.2 mL in the synthesis mixture. Catalysts prepared with a maximum quantity of C18TMS and a minimum quantity of tetraethylorthosilicate exhibited a minimum activity loss of 17.46%.