Development of hydrogen embrittlement resisted pd-cu alloy membrane

Abstract

The development of PdCu alloy membranes that can be used in hydrogen separation at low working temperature (<300°C) without hydrogen embrittlement problem is a very attractive topic for the petrochemical industry. Pd–Cu membranes have been prepared by electroless plating and electroplating method on stainless steel support. The compositions of the PdCu alloy membranes were related to both the metal deposition rates. The appropriate annealing temperature of Pd–Cu membranes was found at 500 °C in argon atmosphere for 24 hours to form a complete alloy material. After thermal annealing, the Cu atom was distributed in Pd alloy membrane. The surface morphology, compositions, and crystallinity of the PdCu alloy membranes were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The best Pd contents in PdCu alloy membrane were about 84 and 75 %at. The hydrogen flux through the PdCu alloy membrane was measured at temperature 150 to 300 °C and differential pressure 0.5 to 2.5 bar for membrane stability. The hydrogen flux increased with increasing temperature and pressure. Adding Cu atoms in Pd can reduce strain in Pd lattice structure. Both PdCu alloy membrane can be operated at the lower temperature than a critical temperature of pure Pd membrane without hydrogen embrittlement.