High performance stainless-steel supported Pd membranes with a finger-like and gap structure and its application in NH3 decomposition membrane reactor

•Supported Pd membranes with enhanced stability by a gap and finger-like structure.•Pd membranes show strong robustness under fast heating up/cooling down cycles.•Nearly complete ammonia conversion at a low temperature of 673 K and 3 bar (ΔP)•Excellent long-term stability test of NH3 decomposition Pd membrane reactor at 673 K.