Answer to Question #3246 in Inorganic Chemistry for kem
Importance of hydrogen bonds in hydrogen economy.
Many experts believe that hydrogen could be used as a fuel source to provide energy to the world. In order for this to happen, the gas must be in itspure form. This is problematic because hydrogen bonds (connect or attache) relatively easily to other elements. In fact, it does not occur as a gas in nature but rather is found in combination with other elements. For example, hydrogen combines with oxygen to form water.
We can identify a number of breakthroughs that have the potential for high impact on the hydrogen economy. The use of improved catalysts have the potential for high impact because of their exp(-E/kT) dependence. Thus, a promising strategy is the search of new catalysts that lower the energy barriers for chemical reactions, can be made in the optimal small sizes (usually in the 2-5nm range), and can contain cheaper and more plentiful elements. An example where such a specially tailored catalyst has been developed for the hydrogen economy is the Pt3M catalyst. Density functional theory was first used to establish the concept of using a Pt surface layer of the catalytic particle to rapidly dissociate a hydrogen molecule. The introduction of a first subsurface layer with a PtM composition then provides a mechanism for attaching atomic hydrogen more easily. Such an approach can provide strong binding and also rapid release on hydrogen. Variants of this concept could have an impact on hydrogen production, storage, and use in fuel cells. An implementation of this general concept has recently been made to increasing the catalytic activity of Pt by a factor of 10 in the oxygen reduction reaction by using a surface Pt layer and a subsurface PtNi layer to break the O-O bonds to form O-H bonds. Weak surface bonds prevent the splitting of O-O bonds, while strong surface bonds attract guest species to adhere to the surface, thereby blocking access of other reactants to the catalyst. In the case of the oxygen reduction reaction, the 10-fold increase in catalytic activity for the oxygen reduction reaction which occurs at the anode of hydrogen fuel cells was achieved by using both the crystal orientation of the catalytic particle and its compositional variatio