Twenty years after: scaling relations in oxygen electrocatalysis and beyond

Since the 2000s, so-called scaling relations have been recognised as a limiting factor in electrocatalysis. Overcoming these constraints is essential to advance energy conversion technologies such as electrolysers, fuel cells, and metal-air batteries. This review presents key concepts, tools, and manipulation strategies required to deal with the scaling relations in oxygen electrocatalysis, chosen as a representative case. Special attention is given to the catalyst's geometry as an emerging central variable in electrocatalysis - one whose influence is only beginning to be systematically understood. Building on geometric and chemical grounds, this review offers a structured tutorial for the theory-driven design of electrocatalysts the deliberate manipulation of scaling relations.