LAUSR

Transition metals, in particular noble metals, are the most common species in metal-mediated water electrolysis because they serve as highly active catalytic sites. In many cases, the presence of non-transition metals, that is, s-, p-, and f-block metals with high natural abundance in the earth-crust in the catalytic material is indispensable to boost efficiency and durability in water electrolysis. This is why alkali metals, alkaline-earth metals, rare-earth metals, lean metals, and metalloids receive growing interest in this research area. In spite of the pivotal role of these non-transition metals in tuning efficiency of water electrolysis, there is far more room for developments towards a knowledge-based catalyst design. In this review, we discuss five classes of non-transition metals species which were successfully utilized in water electrolysis, with special emphasis on electronic structure-catalytic activity relationships and phase stability. Moreover, specific fundamental aspects on electrocatalysts for water electrolysis as well as a perspective on this research field have also been addressed in this account. We anticipate that this review can trigger a broader interest in using s-, p-, and f-block metals species towards the discovery of advanced polymetal-containing electrocatalysts for practical water splitting. This article is protected by copyright. All rights reserved.