This Small Business Innovation Research (SBIR) Phase I project focuses on the development of an innovative diffusion barrier for the preparation of Pd thin film on tubular porous stainless steel substrate. A thin Pd film supported on tubular porous SS substrate provides a commercially viable avenue for the use of palladium membranes for hydrogen production/recovery, particularly for large-scale applications. A micro-engineered diffusion barrier is proposed, which is able conceptually to accommodate the physical change of metal substrate surface, thermal mismatch, and other factors. More importantly this diffusion barrier offers flexibility in tailoring its pore size and surface topography to be optimal for the formation of an ultra-thin, defect free, and strongly adhered Pd film via electroless plating. <br/><br/>The proposed diffusion barrier could offer a practically viable Pd-based hydrogen separation device, which can benefit fuel cell and industrial hydrogen applications, and greenhouse gas reduction.