The manufacture of hydrogen peroxide, on a large or a small scale, inevitably involves hydrogen atom transfer to oxygen — traditionally to the oxygen atoms of quinones. While the hydrogen atoms that are transferred have traditionally come from hydrogen gas, it is more practical on a small scale to take them from an organic solvent like toluene, which can be done if the excited state of a quinone is used. A photochemical process will generate hydrogen peroxide on a continuing basis in a flow system, and allow its facile extraction by water. The immobilization of a quinone will make the separation easier. Computer simulations of the biphasic systems being developed will make their optimization easier.
The transfer of hydrogen atoms to quinones from hydrogen gas can also be used in hydrogen storage reactions. The hydrogenation of anthraquinone to the corresponding hydroquinone can be catalyzed by a cobalt complex, and the dehydrogenation to benzoquinone of the corresponding hydroquinone can be catalyzed by the same complex. The equilibrium constants for many quinone/H2 vs hydroquinone equilibria will be examined computationally, and thereby choose the ones most suited to hydrogen storage and retrieval.
Related hydrogen transfers will also be explored with large anions to induce lithium cations to dissolve in organic solvents, allowing the evaluation of such cations (Li+) to catalyze the transfer of hydrogen atoms from H2 to quinones. Furthermore, the ability of ammonia borane to generate hydrogen gas in flow systems in polar solvents will be investigated. Copper catalysts will be pursued for the regeneration of ammonia borane from dehydrogenated materials and hydrogen gas.
