I believe this is false. Hydrogen is the most abundant element in the universe, but not on Earth. If it were, we would be a gas planet.
That said, hydrogen is a very abundant element on Earth, but it is not at all abundant beyond water molecules. And that H2O requires a great deal of energy to split, more than you can get from burning hydrogen.
Oxygen, followed by silicon, is the most abundant element on earth........SO I guess Silicon Dioxide is THE most abundant mineral on earth, sand..............