Addressing electrocatalytic activity and stability of LnBaCo(2)0(5+delta) perovskites for hydrogen evolution reaction by structural and electronic features

Herein the structural versatility is allowed to correlate with electrocatalytic properties of the perovskites. We report LnBaCo(2)O(5+delta) (Ln = lanthanide) perovskites as highly active electrocatalysts for hydrogen evolution reaction (HER). The tolerance factor (t(f)) and O p/Co d-band centers are proposed to be efficient descriptors for addressing their electrochemical performance. The t(f) endows the HER activity/stability with a volcano shape for our synthesized double/simple perovskites. The O p/Co d-band centers locating far from the Fermi level (E-F) results in the best activity of LnBaCo(2)O(5+delta) among the LnBaCo(2)O(5+delta) perovskites. The outstanding stability can be explained by having the O p/Co d-band centers neither close to nor far from the E-F. The maximum HER activity benefits from optimal free energy combination for the adsorption/dissociation of H2O and desorption of -OH/H*. The proper t(f) values and O p/Co d-band centers may realize synergistic interplay, which is crucial to reasonably design the oxide materials.

Automated summary

In this study, LnBaCo(2)O(5+delta) perovskites were reported as highly active electrocatalysts for the hydrogen evolution reaction (HER), with the tolerance factor and O p/Co d-band centers proposed as efficient descriptors for their electrochemical performance. The optimal HER activity is achieved through a combination of free energies for the adsorption/dissociation of H2O and desorption of -OH/H*, facilitated by appropriate tolerance factor values and O p/Co d-band centers.