A hollow-fibre catalytic membrane developed by researchers in China and Germany could scrub the greenhouse gas nitrous oxide from the exhausts of chemical plants.
The membrane has a type of crystal structure known as perovskite, and contains barium, cobalt, iron and zirconium. It catalyses the breakdown of nitrous oxide to free nitrogen gas and oxygen atoms, which end up bound to its surface. These atoms recombine into molecular oxygen too slowly to avoid clogging up the membrane and slowing the process. Adding methane to the system solves this problem because it mops up the oxygen as it forms. This reaction generates 'synthesis gas', a mixture commonly used in industry as a fuel or chemical feedstock.
The system's architects, Haihui Wang from South China University of Technology in Guangzhou and his colleagues, say that their membrane is the first from which oxygen can be removed quickly enough to avoid attenuating the membrane's catalytic effect.