Enhanced Hydrogen Permeability of Mixed Protonic–Electronic Conducting Membranes through an In‐Situ Exsolution Strategy
Guowei Weng, Kun Ouyang, Xuanhe Lin, Sisi Wen, Yisa Zhou, Lei Song, Jian Xue, Haihui Wang
Abstract
Abstract Mixed protonic–electronic conducting (MPEC) ceramic membranes with high H 2 permeability and stability are significant for practical H 2 separation. CO 2 ‐tolerant lanthanum tungstate oxides have received much attention, but their low H 2 permeability is their main problem for membrane applications. Herein, an efficient in‐situ exsolution strategy is proposed to enhance the H 2 permeability and CO 2 stability of lanthanum tungstate‐type membranes. During H 2 permeation, the catalytic Pd nanoparticles are in‐situ generated from the bulk oxide lattices and dispersed evenly on the membrane surfaces, which greatly promotes the H 2 surface exchange kinetics. Also, the protonic conductivity of the membranes is effectively improved through the introduction of Pd. Consequently, the H 2 permeation flux is increased by 3.5 times and a maximum H 2 flux of 1.3 mL min −1 cm −2 is achieved at 1000 ° C through the La 5.5 (W 0.6 Mo 0.4 ) 0.95 Pd 0.05 O 11.25‐δ (LWMPd) membrane. The LWMPd membrane shows outstanding long‐term chemical stability during 300 h continuous operation in a CO 2 ‐containing atmosphere. Therefore, this in‐situ exsolution formation of Pd nanoparticles provides effective guidance for developing competitive MPEC membranes for H 2 separation and purification.