Methyl Iodide Adsorption on Reduced Silver-Functionalized Silica
Aerogel: How Temperature Impacts the Adsorption?
To understand the effect of temperature to the adsorption, 104 ppbv and
1044 ppbv methyl iodide (CH3I) adsorptions on reduced
silver-functionalized silica aerogel (Ag0-Aerogel) at
100, 150 and 200 ℃ were performed. In the experiments, a significantly
high uptake rate (3 – 4 times higher than that at 100 and 150 ℃) was
observed for the 104 ppbv adsorption at 200 ℃. To explain such behavior,
a potential reaction pathway was proposed and multiple physical analyses
including nitrogen titration, x-ray photoelectron spectroscopy (XPS) and
scanning electron microscopy (SEM) were performed. Based on the results,
the contributing factors appear to be the formation of different Ag-I
components induced by temperature, higher silver site availability,
decreasing diffusion limitation, and increasing reaction rate described
by the Arrhenius relationship.