The study is dedicated to catalysts on the base glass microfibrous supports. It discusses the issues of the diffusion of reactants in the bulk of glass fibers, using the model reaction of toluene deep oxidation in air at Pt-containing glass-fiber catalyst (GFC). The catalysts with location of Pt particles either at the external fiber surface or in the hypothetical sub-surface layers in the glass bulk are compared. The intra-fiber diffusion of toluene is considered from positions of diffusion in liquid, interpreting glass as super-cooled liquid with high viscosity. The calculations show that at moderate temperatures the diffusion coefficient and corresponding efficiency factor are extremely low due to very high viscosity of high-silica glasses. The apparent reaction rate at sub-surface Pt particles appears to be dramatically lower (by 7-10 orders of magnitude) than that for the surface Pt. It is concluded that even if the sub-surface metal particles really exist, their contribution to the overall performance of GFC is negligible. This result disproves the notion stating that properties of some class of GFCs are defined by sub-surface particles of active component.

该研究致力于基玻璃微纤维载体上的催化剂。通过使用甲苯在含Pt的玻璃纤维催化剂（GFC）中在空气中进行深度氧化的模型反应，讨论了反应物在玻璃纤维主体中的扩散问题。比较了Pt颗粒在玻璃纤维外表面或假设的次表面层中的位置的催化剂。从液体中的扩散位置考虑甲苯在纤维内的扩散，将玻璃解释为具有高粘度的过冷液体。计算表明，由于高硅玻璃的粘度很高，因此在中等温度下扩散系数和相应的效率因数极低。亚表面Pt颗粒的表观反应速率似乎比表面Pt的显着降低（降低了7-10个数量级）。结论是，即使表面下金属颗粒确实存在，它们对GFC整体性能的贡献也可以忽略不计。该结果反驳了认为某些类型的GFC的性质由活性成分的表面下颗粒定义的概念。