Hydrogen (H2) is a promising fuel for reducing greenhouse gases, especially if produced by using renewable energy to split water molecules (H2O). But as simple as it may seem to break water into hydrogen and oxygen, the chemistry is complex. Hydrogen (H2) is a promising fuel for reducing greenhouse gases, especially if produced by using renewable energy to split water molecules (H2O). But as simple as it may seem to break water into hydrogen and oxygen, the chemistry is complex. Analytical Chemistry Materials Science Phys.org – latest science and technology news stories