Nanoporous Membranes for Hydrogen Production : Experimental Studies and Molecular Simulations

In this project, we study SiC nanoporous membranes, which exhibit the potential to overcome many of the difficulties other inorganic membranes face, particularly under conditions typically encountered in reactive separations for H2 production, and in fuel-cell applications. In particular, we systematically investigate and further develop the technique of pre-ceramic polymer pyrolysis to produce nanoporous SiC membranes and films, which are both cost-efficient and industrially viable. Our efforts are motivated by the growing interest in the H2 economy, which necessitates the development of robust nanoporous materials for use in high-temperature and pressure processes related to H2 production. SiC is a promising material for such applications, due to its many unique properties, such as high thermal conductivity, thermal shock resistance, chemical inertness and high mechanical strength. The main focus of our project is on trying to understand the formation process of the membranes, namely, how the initial structure of the polymeric precursor and the pyrolysis conditions impact the final membrane characteristics. Our efforts involve extensive experimental investigation of the membrane formation process, as well as modeling of the pyrolysis process itself by molecular dynamics simulations, since the understanding must be at the molecular level. The new science that is being developed impacts not only the fabrication of SiC membranes, but also the general field of inorganic membranes, including carbon molecular-sieve (CMS) and mixed-matrix membranes. A key outcome of our effort will be the ability to prepare a membrane with certain “optimal” properties (e.g., permeance, separation factor, and surface characteristics) by being able to determine in a systematic way the type of polymeric precursor one needs to use, and the preparation method and procedure that one must utilize.