Amorphous silica molecular sieving membranes by sol‐gel processing

Microporous ceramics and ceramic membranes have many potential applications, for example, in the chemical, environmental, energy conversion, and automotive industries. An organic template approach using sol‐gel processing is described by which microporous amorphous silica is synthesized. It is shown that the very narrow pore size distribution is comparable to that of the zeolite ZSM‐5 and that the membranes have ideal gas separation factors at least two orders of magnitude larger than those expected for a Knudsen diffusion separation mechanism.