The Sabatier principle establishes a fundamental trade-off in heterogeneous electrocatalysis. In the hydrogen evolution reaction (HER), this trade-off is manifested by the coupling of the Volmer step, which requires strong hydrogen adsorption, with the Heyrovsky/Tafel step, which favors facile desorption—thus giving rise to the classical volcano relationship and limiting activity even at ΔGH*≈ 0. Here, we demonstrate a ferroelectric platform with dynamic tunability—monolayer GeS2 decorated with transition-metal atoms as a proof-of-concept—where polarization-driven surface electronic reconstruction enables real-time modulation of intermediate binding strength, thereby breaking the Sabatier constraint. Reversible control of hydrogen adsorption allows strong H* binding to accelerate the Volmer step, followed by weakened adsorption to promote the Heyrovsky/Tafel step. This dynamic adsorption–desorption decoupling not only surpasses the volcano limit to achieve unprecedented HER activity but also establishes a general paradigm for designing adaptive electrocatalysts capable of reconfiguring under operating conditions.