  Hydrogen embrittlement in metals (HE) is a serious challenge for the use of
high strength materials in engineering practice and a major barrier to the use
of hydrogen for global decarbonization. Here we describe the factors and
variables that determine HE susceptibility and provide an overview of the
latest understanding of HE mechanisms. We discuss hydrogen uptake and how it
can be managed. We summarize hydrogen trapping and the techniques used for its
characterization. We also review literature that argues that hydrogen trapping
can be used to decrease HE susceptibility. We discuss the future research that
is required to advance the understanding of HE and hydrogen trapping and to
develop HE-resistant alloys.
