Exploring the absorption of gas in palladium
Palladium is a metal that can act like a sponge for gases. This means that a gas could be stored within a metal and then later removed for use in chemical reactions, fuel cells, and other applications.
In this research, palladium was spread out as tiny particles across a host material of very high surface area. This maximizes how much of the palladium can be exposed to gases of interest. The physical characteristics of the supported palladium and host material was investigated using a variety of techniques including scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy.
The maximum amount of hydrogen gas that can be stored in and removed from the supported palladium was determined in a specially-designed set of stainless steel chambers held at a constant temperature. It was found that supported palladium can absorb gas at an average ratio of 0.89 molecules of hydrogen per molecule of palladium. This is 30% more hydrogen than was absorbed by unsupported particles of palladium oxide (palladium black). A similar experiment performed on the support material alone showed that it does not take up any hydrogen by itself.
Other researchers found that different amounts of gases including hydrogen can be absorbed by different combinations of metal and support material. Coupled with the current research, this suggests that additional gains can be made in terms gas storage using solid metals. This has exciting implications for many different applications including gas storage and fuel cells.