A high-performance, H2-permselective silica membrane derived from hexyltrimethoxysilane (HTMOS) was developed for application in the thermochemical water-splitting iodine–sulfur process. Silica membranes, referred to here as HTMOS membranes, were prepared via counter-diffusion chemical vapor deposition on γ-alumina-coated α-alumina support tubes with outer diameters of 10 mm. Special attention was devoted to obtain high H2/HI selectivity, high H2 permeance, and good stability in the presence of corrosive HI gas. The effects of the deposition conditions, temperature, and period were investigated. The HTMOS membrane prepared at 450 °C for 5 min exhibited high H2/HI selectivity (>175) with H2 permeance on the order of 10−7 mol Pa−1 m−2 s−1. On the basis of stability experiments, it was found that the HTMOS membrane was stable upon HI exposure at a temperature of 400 °C for 11 h.
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Condensed Matter Physics
- Energy Engineering and Power Technology