The low concentration methyl iodide (CH₃I) adsorption process on reduced silver‐functionalized silica aerogel (Ag⁰‐Aerogel) was studied. The kinetic data were acquired using a continuous flow adsorption system. Because the corresponding physical process was observed, the shrinking core model (SCM) was modified and applied. An average CH₃I pore diffusivity was calculated, the CH₃I‐Ag⁰‐Aerogel reaction was identified as a 1.40 order reaction instead of first order reaction, and the n^th order reaction rate constant was determined. This modified SCM significantly increases the accuracy of adsorption behavior prediction at low adsorbate concentration. Modeling results indicate that the overall adsorption process is controlled by the pore diffusion. However, at low adsorbate concentration (ppbv level), the CH₃I adsorption is limited to the surface reaction due to the low uptake rate in a predictable time period.

中文翻译：

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甲基碘在还原的银官能化二氧化硅气凝胶上的吸附：动力学和模型

研究了还原的银官能化二氧化硅气凝胶（Ag ⁰ -Aerogel）上低浓度甲基碘（CH ₃ I）的吸附过程。使用连续流吸附系统获得动力学数据。由于观察到了相应的物理过程，因此修改并应用了收缩核心模型（SCM）。平均CH ₃我孔扩散率计算时，CH ₃ I-的Ag ⁰ -Aerogel反应被确定为1.40次序反应，而不是一级反应，并且Ñ^第确定反应速度常数。这种改进的SCM大大提高了在低吸附物浓度下吸附行为预测的准确性。建模结果表明，整个吸附过程受孔隙扩散的控制。但是，在低的吸附物浓度（ppbv水平）下，由于在可预测的时间段内摄取率低，因此CH ₃ I吸附仅限于表面反应。