About 5-6 years ago the news included a story about a guy by the name of John Kanzius who fired radio waves at salt water and got hyrdogen out of the water.
Here's utube of the story
Likely the radio waves were tuned to something like 12.5 or close to whatever is the NMR nuclear magnetic resonance of hydrogen--and thereby shook them out of the H2O bonds.
It was an interesting experiment. The problem was that it took more energy to cause the reaction than energy was produced. I've seen numbers for the energy in out shortfall as being anywhere from 10%-70%.
There was an enormous amount of publicity about the procedure at the time. But after a year or so, the news died back to nothing. It doesn't seem like anyone ever tried to optimize the process. Kanzius died a couple years later.