Why it is difficult to get hydrogen gas from air?

Answer 1

Hydrogen gas only exists in the atmosphere in trace amount. The hydrogen in water vapor, which is more abundant, is chemically bound to the oxygen in the molecule and thus require large amounts of energy to extract.

Answer 2

Hydrogen gas is not naturally abundant in the atmosphere, making it difficult to extract in significant quantities. Air is primarily composed of nitrogen and oxygen, with only trace amounts of hydrogen. To obtain hydrogen gas from air, energy-intensive processes such as electrolysis or steam methane reforming are typically required.