Palladium Membrane Fabrication via Colloidal Deposition

The patent replaces the mechanical sputtering process with a chemical deposition process using colloidal Pd particles. Instead of using physical sputtering under high vacuum to deposit Pd atoms, the invention uses a chemical solution containing stabilized Pd colloids that can be applied via simple coating methods and then sintered to form dense films. This substitution of mechanical deposition with chemical deposition dramatically reduces fabrication time while maintaining film density.

The patent changes the physical and chemical parameters of the Pd deposition process by using colloidal particles with specific size distributions and surface stabilizations. By controlling particle size, surface charge, and colloidal stability, the process achieves dense film formation at lower temperatures and shorter times compared to conventional sputtering, resolving the time-density contradiction.

The patent uses inexpensive colloidal Pd particles as the deposition source instead of expensive metal organic chemicals required for CVD. The colloidal particles are simple, stable suspensions that can be applied directly without complex precursor chemistry, reducing both material cost and process complexity while maintaining film uniformity through controlled particle deposition and sintering.

The patent introduces colloidal particles as an intermediary between the Pd source and the substrate. These colloids serve as stable, controllable carriers of Pd that simplify the deposition process compared to CVD gas-phase chemistry. The colloidal intermediary enables uniform film formation through liquid-phase application followed by sintering, avoiding complex CVD process conditions.

The patent applies local quality by using small pores in the substrate support structure to ensure mechanical integrity and prevent pinholes, while forming a continuous, dense Pd thin film layer on the substrate surface that provides the actual hydrogen separation function. The Pd film quality is locally optimized to be pinhole-free and dense, while the substrate pores can be larger for reduced diffusion resistance, resolving the contradiction between selectivity and diffusion resistance.

The patent creates a composite membrane system consisting of a porous substrate support combined with a dense Pd thin film layer. The substrate provides mechanical strength and can have larger pores for reduced diffusion resistance, while the Pd film layer provides the selective hydrogen separation barrier without pinholes. This composite structure allows optimization of each component's properties independently, resolving the selectivity-diffusion resistance contradiction.