Topological nodal lines-driven intrinsic oxygen evolution activity in monolayer YTe

Identifying low-cost, high-performance electrocatalysts for the oxygen evolution reaction (OER) is crucial for sustainable hydrogen production. Here, using first-principles calculations, we predict that the two-dimensional topological nodal-line (NL) semimetal YTe, a monolayer rare-earth monochalcogenide, is a near-ideal OER catalyst, with its intrinsic overpotential (η= 0.37 V) sitting near the apex of the activity volcano. Furthermore, we find that its catalytic performance is strongly tied to its topological electronic structure, the NLs near the Fermi level and surface density of states (SDOS) for topological surface states (TSSs), rather than to the conventionald-band center descriptor. Thus, destroying the NL through symmetry breaking markedly degrades the catalytic activity, and shifting the NL away from the Fermi level also weakens the OER performance. This behavior can be attributed to the reduction in the SDOS associated with the TSSs. We further investigate compounds sharing the same crystal structure as YTe, MX (M = Sc, Y; X = S, Se, Te), and reveal that symmetry breaking generally weakens their catalytic activity. This work not only identifies a highly active topological catalyst for OER, but also establishes a theoretical basis for designing next-generation topological catalysts.