Effect of plasma nitriding on the structural stability and hydrogen absorption capability of Pd-coated Nb during thermal treatment

•Pd-coated Nb alloy is a promising material for hydrogen-permeable membrane.•Plasma nitriding was explored for suppressing the interdiffusion between Pd and Nb.•Intermediate layer by plasma nitriding suppressed the interdiffusion effectively.•The hydrogen permeability of the intermediate layer was significantly low.