Numerical simulation of bubble behavior on dual microelectrode surfaces regulated by pulsed current parameters

• 1、College of Chemistry and Chemical Engineering, Chongqing University, Chongqing，401331

Abstract：Driven by the energy transition, hydrogen is a key clean energy source for achieving deep decarbonization. Although water electrolysis is the mainstream green hydrogen production technology, hydrogen bubbles on the electrode surface can block active sites and reduce efficiency. Pulsed electrolysis regulates bubble behavior by periodically turning the current on and off, with duty cycle and period serving as key parameters. This paper adopts a numerical simulation method to investigate the effects of pulse current duty cycle and period on dual bubbles behavior. As the duty cycle increases from 0.1 to 0.9, the contact radius of bubbles prior to coalescence grows faster and reaches a larger final value, with the fastest growth and largest final radius observed under constant current conditions; both the pre-coalescence growth time and detachment time decrease, while the detachment diameter increases, with the shortest time and largest diameter observed under constant current. As the period increases from 0.001 s to 0.016 s, the pre-coalescence bubble contact radius grows faster, with the fastest growth occurring under constant current; the pre-coalescence growth time and detachment time first increase and then decrease, with the shortest durations under constant current. The fluid velocity around the bubbles rises when the pulse current is on and decreases when off; under constant current, the velocity increases continuously, and the peak velocity of the pulse current is always lower than that of the constant current at the same time. This study provides theoretical support for the design of pulsed electrolysis processes for hydrogen production via water electrolysis.

Keywords： Dual-bubble Phase-field method Pulse parameter Multiphysics coupling Numerical simulation