The Potential of Zero Charge: An Interfacial Descriptor Governing Hydrogen Evolution Reaction on Bulk Metal Electrodes

While the Sabatier‐based volcano plots guide catalyst design for Hydrogen Evolution Reaction (HER), the purely thermodynamic hydrogen binding energy descriptor fails to capture experimental HER trends accurately due to the omission of kinetic contributions. Herein, we combine the fixed‐potential method with our developed continuous proton supply/consumption model to establish an extra kinetic descriptor for metal‐based electrodes (Pt, Pd, Au, Ag, and their bimetallic alloys) under practical working conditions. The potential of zero charge (PZC) is demonstrated to be the interfacial descriptor, which modulates surface charge density and thereby tunes the kinetic proton enrichment within the EDL. Building on this insight, the PZC is integrated with hydrogen binding energies to establish a new two‐dimensional volcano plot for HER. The updated volcano plot derived from the dual descriptors effectively matches the experimental results, which provides an additional guiding parameter for rational catalyst design.