hydrogendrift

Hydrogendrift is a term used in several scientific disciplines to denote the directed transport of hydrogen species, typically molecular hydrogen (H2) or protons (H+), under non-equilibrium conditions. It emphasizes that hydrogen movement can exhibit a net flow rather than purely random diffusion.

The drift component arises from external forces or fields, such as electric fields, pressure gradients, buoyancy, concentration gradients, or temperature gradients. In practice, hydrogen transport is described by drift-diffusion models that combine Fickian diffusion with field-driven flux, as formalized in equations like the Nernst-Planck relation for charged species.

Hydrogendrift is relevant in metal hydride storage, fuel cells, and gas separation membranes, where hydrogen mobility affects performance and reliability. It also appears in electrochemistry, where proton drift occurs in electrolytes, and in geochemical and environmental contexts, where hydrogen migrates through rocks, soils, or organic matrices. In plasma physics, hydrogen ions can drift under magnetic and electric fields.

Quantifying hydrogendrift involves parameters such as diffusivity, solubility, permeability, and trapping effects. Experimental methods include diffusion tests, spectroscopy, and scanning-probe or mass-spectrometric techniques; models rely on Fick's laws, Nernst-Planck equations, and more comprehensive drift-diffusion frameworks.

The term hydrogendrift is not universally standardized; some writers refer to hydrogen diffusion or hydrogen migration, depending on context. The label is typically used to highlight directed transport components in systems where hydrogen movement influences material behavior or device performance.