Yan Erhu, Huang Guanzhong, Zhang Kexiang, Tao Lizhen, Chen Hongfei, Guo Zhijie, Zhang Shuo, Wang Yihao, Zhou Zirui, Li Tangwei, Sun Lixian
Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin 541004, China.
Department of Energy, Materials and Telecommunications, INRS-EMT, Quebec, QC J3X 1S2, Canada.
Membranes (Basel). 2024 Dec 2;14(12):253. doi: 10.3390/membranes14120253.
Currently, the main limitations of Pd-coated Nb-TiFe dual-phase alloys include insufficient hydrogen permeability, susceptibility to hydrogen embrittlement (HE), and poor tolerance of HS poisoning. To address these issues, this study proposes a series of improvements. First, a novel NbTiFe alloy composed of a well-aligned Nb-TiFe eutectic was successfully prepared using directional solidification (DS) technology. After deposition with a Pd catalytic layer, this alloy exhibits high hydrogen permeability of 3.71 × 10 mol H m s Pa at 673 K, which is 1.4 times greater than that of the as-cast counterpart. Second, to improve the HS corrosion resistance, a new PdAu catalytic layer was deposited on the surface using a multi-target magnetic control sputtering system. Upon testing in a 100 ppm H/HS mixture, this membrane exhibited better resistance to bulk sulfidation and a higher permeance recovery (ca. 58%) compared to pure Pd-coated membrane. This improvement is primarily due to the lower adsorption energies of the former with HS, which hinders the formation of bulk PdS. Finally, the composition region of the Pd-Au catalytic membrane with high comprehensive performance was determined for the first time, revealing that optimal performance occurs at around 12-18 at.% Au. This finding explains how this composition maintains a balance between high H permeability and excellent sulfur resistance. The significance of this study lies in its practical solutions for simultaneously improving hydrogen permeability and resistance to HS poisoning in Nb-based composite membranes.
目前，钯包覆的铌钛铁双相合金的主要局限性包括氢渗透率不足、易受氢脆（HE）影响以及对硫化氢中毒的耐受性差。为了解决这些问题，本研究提出了一系列改进措施。首先，采用定向凝固（DS）技术成功制备了一种由排列良好的铌钛铁共晶组成的新型铌钛铁合金。在沉积钯催化层后，该合金在673 K时表现出3.71×10⁻³ mol H₂ m⁻² s⁻¹ Pa⁻¹的高氢渗透率，是铸态合金的1.4倍。其次，为了提高抗硫化氢腐蚀性能，使用多靶磁控溅射系统在表面沉积了一种新的钯金催化层。在100 ppm H₂/H₂S混合物中测试时，与纯钯包覆膜相比，该膜表现出更好的抗整体硫化性能和更高的渗透恢复率（约58%）。这种改进主要是由于前者与硫化氢的吸附能较低，阻碍了块状硫化钯的形成。最后，首次确定了具有高综合性能的钯金催化膜的成分范围，发现最佳性能出现在约12 - 18 at.%的金含量附近。这一发现解释了这种成分如何在高氢渗透率和优异的抗硫性之间保持平衡。本研究的意义在于为同时提高铌基复合膜的氢渗透率和抗硫化氢中毒性能提供了实际解决方案。
