The increasing demand for renewable energy systems has intensified interest in hydrogen production via water electrolysis. Accumulation of gas bubbles on electrode surfaces increases ohmic resistance and lowers overall efficiency. One approach to enhance the bubble detachment is the application of ultrasonic pressure waves [1] to induce controlled bubble oscillations. In this work, we investigate the dynamics of a gas bubble located near a rigid surface and separated from it by a thin liquid layer, such that no static contact angle is defined. The bubble is subjected to a harmonic pressure excitation representing an ultrasonic wave. The influence of excitation frequency and amplitude on bubble oscillations is studied. For a given bubble radius, a natural oscillation frequency exists, which is altered by the proximity of the wall. Oscillations must be sufficiently strong to promote detachment while avoiding violent collapse. First, a modified Rayleigh-Plesset model [2] incorporating near-wall effects is employed to analytically estimate the natural frequency and predict the radial response of the bubble under harmonic forcing. Subsequently, numerical simulations are performed using the compressibleInterFoam solver in the OpenFOAM framework to capture nonlinear bubble dynamics, deformation, and radius change. Analytical predictions are compared with numerical results for validation. The results reveal the existence of an optimal excitation frequency close to the modified natural frequency of the near-wall bubble, at which the oscillation amplitude is maximized. Increasing the bubble radius shifts the optimal frequency toward lower values. These findings demonstrate that tuning ultrasonic excitation to the near-wall natural frequency can enhance bubble detachment while mitigating collapse, offering a pathway to improved electrolyzer efficiency.