Hydrogenuptake

Hydrogenuptake is the process by which hydrogen from the environment is absorbed into a system, whether a solid, liquid, or living organism. It includes surface adsorption, dissolution into a bulk phase, and diffusion within the material or organism. The term is used in both materials science and biology to describe absorption that affects function and properties.

In metals and solids, uptake involves surface exchange, diffusion into the lattice, and possible formation of metal hydrides. Solubility often increases with pressure and decreases with temperature, and in many systems follows Sievert's law. Microstructure, defects, and catalysts influence uptake rates. Excess hydrogen can cause embrittlement, phase changes, or altered mechanical behavior. Measurements include gravimetric uptake, pressure–composition isotherms, and spectroscopic or neutron methods.

In microbial and plant contexts, hydrogen uptake commonly occurs via hydrogenases or diffusion across membranes, enabling H2 to act as an electron donor or signaling molecule. Uptake rates depend on enzyme activity, cellular redox state, and environmental conditions. In some organisms, hydrogen uptake supports energy production under anaerobic conditions or lithoautotrophic growth.

Understanding hydrogen uptake informs the design of hydrogen storage materials and safe operation of hydrogen technologies, as well as biomedical research on inhaled hydrogen. It also underpins assessment of embrittlement risks and informs measurement standards in research and industry.