THE SCIENCE AND TECHNOLOGY OF AL-GA ALLOYS AS A MATERIAL FOR ENERGY STORAGE, TRANSPORT AND SPLITTING WATER

摘要

Currently, there is much public discussion about the realization of a hydrogen economy as a viable alternative for future large-scale energy sources. Hydrogen as an energy source has several compelling features. For example, its gravimetric energy density is three times that of oil, its combustion and fuel cell product is usually water and, hence, does not leave a carbon footprint, and its abundance, as water is plentiful. Offsetting these advantages are for example, the flammability of hydrogen, its low energy density as a highly compressed gas, the large scale impracticality of containment as a low temperature liquid, and the current commercial nonviability of its storage either via absorption, e.g. as a metal hydride or as a chemical reaction, e.g. borohydrides. The storage absorption and chemical reaction issues are discussed on the Department of Energy website. In our presentation we present what we consider to be a safe and economically viable technology for energy storage, transport and splitting water to make hydrogen on demand using Al-Ga alloys. The essence of our technology is the depassivation of Al by alloying Al with Ga. This allows Al to readily split water into hydrogen, alumina, and heat. The general concept is to form a material with a component that is inherently capable of splitting water, e.g. Al, which also contains a component, e.g. Ga, which will not split water, but will depassivate the surface of the water splitting component. We will discuss the origin of our project and two examples of recent technology innovations.