NOVELTY - The method involves applying cationic surfactant i.e. cetyl trimethyl ammonium bromide (CTAB), to a palladium plating bath. Palladium electroless plating is subjected to sonication in an ultrasonic cleaning bath. A contacting pattern of reducing agent i.e. hydrazine hydrate, is optimized during plating process. The cationic surfactant is applied to electroless plating (ELP) baths in concentration of 2 to 4 times of critical micelle concentration (CMC), where concentration of palladium solution is varied from 0.005 - 0.01 M.    USE - Method for preparing a dense or near dense palladium/PSS membrane used in insitu hydrogen generators, membrane reactors and guard units to proton exchange membrane fuel cells (PEMFC), by electroless plating.    ADVANTAGE - The method enables electroless plating of dense palladium membranes and supported noble metal catalysts with lower concentrations of palladium in an easy, convenient and simple manner, scalable, cost effective and generic toward applicability of developed process for deposition of noble metals on porous structures so as to enhance plating rates and plating efficiencies with scale-up adaptability. The method enables adding the cationic surfactants to plating solution to increase wettability of a substrate surface and reduce interfacial tension between generated gas bubbles and a deposited substrate and surface tension of the bath for enhancing removal of size reduced gas bubbles quickly without shear stress and form pit free palladium film deposits. The method avoids the cationic surfactants to perform reaction to drive reversible reaction in forward direction to enhance plating rate, thus reducing pitting effect.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a composition for preparing dense or near dense palladium/PSS membrane by electroless plating.    DESCRIPTION OF DRAWING(S) - The drawing shows a graph of effect of surfactant, sonication and surfactant coupled sonication palladium electroless plating baths on time dependent variation of percent pore densification for phase-wise addition of reducing agent.