How advances in theoretical chemistry meet industrial expectations in electrocatalysts for water splitting

Fundamental knowledge about heterogeneous catalysis has significantly advanced in the last few years due to the awareness of the role of non-weakly correlated electrons in open-shell magnetic catalysts, and their degrees of freedom (charge, spin, orbital and structure). Such recognition represents a paradigm shift, because it proves the existence of non-linear oscillations with orbital filling, and also feasible deviations from the Bell-Evans-Polanyi (BEP) principle. By including all the relevant quantum interactions, orbital engineering seeks to identify potentially successful catalysts aprioristically by first principles. The approach does not include nor admit shortcuts. Two steps are needed to narrow down the synthetic quest for optimal catalysts (via orbital configurations), to boost and, concomitantly, fully understand catalytic activities: 1) obtaining the electronic properties, bond topology, populations, magnetic (spin-orbital ordering) structure to infer stability and reactivity, and 2) achieving complete mechanistic insights. Thus, quantum chemistry can be a powerful tool to reinforce traditional industrial developments in water electrolysis and accelerate catalytic designs by implementing physical rationality, while reducing considerably time and waste. This perspective intends to clarify the electrocatalytic challenges in using water electrolysers (WEL), and the advanced computational approaches to tackle them from the perspective of industrial needs. In electrolysers about 10-15% of CAPEX per kg_H2 h-1 is possible via optimizing spin-potentials: a seed from quantum correlations.