氢分离与CO催化甲烷化双功能型钯复合膜  

Bifunctional palladium composite membrane for hydrogen separation and catalytic CO methanation

作　　者：胡小娟[1] 严文俊[1] 丁维华[1] 俞健[1] 黄彦[1] 

机构地区：[1]南京工业大学化学化工学院材料化学工程国家重点实验室,江苏南京210009

出　　处：《催化学报》2013年第9期1720-1729,共10页

基　　金：江苏省高校自然科学基金(09KJA530003);中国博士后科学基金(2011M501220);江苏省博士后科研资助计划(1102090C)~~

摘　　要：以多孔Al2O3陶瓷为基体材料,采用浸渍法担载NiO后用2B铅笔修饰NiO/Al2O3表面,通过化学镀法沉积约5μm厚的金属钯,还原后成功制得Pd/Pencil/Ni/Al2O3膜.为进行对比,还制备了未担载镍的Pd/Pencil/Al2O3膜.膜的表面和断面形貌分别采用扫描电镜和金相显微镜观测,膜的透氢动力学通过H2/N2单气体法测试,并以成分为H277.8%,CO5.2%,CO213.5%和CH43.5%的原料氢测定了膜的氢分离效果.结果表明,未载镍的Pd/Pencil/Al2O3膜只具有氢分离作用,而Pd/Pencil/Ni/Al2O3膜还可以有效地将钯膜泄漏的CO和CO2转化为甲烷,因而成为双功能型钯膜.这种双功能膜尤其适用于面向质子交换膜燃料电池(PEMFC)的氢气分离,既有效解决了PEMFC对氢燃料中CO格外敏感的难题,又提高了对钯膜缺陷的容忍度,因而延长了钯膜的使用寿命.NiO was introduced into the porous Al2O3 substrate by impregnation, and the resulting NiO/Al2O3 was coated with the lead of a 2B pencil to modify its surface. A palladium layer with a thickness of 5 μm was deposited by electroless plating on the Pencil/NiO/Al2O3 substrate, and a Pd/Pencil/Ni/ Al2O3 membrane was obtained after reduction with hydrogen. For reference, a Ni-free Pd/Pencil/ Al2O3 membrane was also fabricated. The surface and cross-sectional morphologies of the membranes were studied by scanning electron microscopy and metallographic microscopy. The hydrogen permeation kinetics was investigated by single gas tests, and the hydrogen separation performances of the Pd/Pencil/Al2O3 and Pd/Pencil/NiO/Al2O3 membranes were tested with a hydrogen feed composed of H 2 77.8%, CO 5.2%, CO2 13.5%, and CH4 3.5%. The Ni-free Pd/Pencil/Al2O3 membrane only shows function of hydrogen separation, while the Pd/Pencil/Ni/Al2O3 is also catalytically effective for methanation of CO and CO2 in hydrogen, forming a bifunctional palladium membrane concept. Since the amount of CO and CO2 in the hydrogen after membrane separation is very low, the consumption of hydrogen by the methanation reactions is negligible. The bifunctional membrane is promising for proton exchange membrane fuel cells because the catalytic methanation treatment solves the CO poisoning problem of the fuel cell electrodes and consequently allows the palladium membrane to tolerate more membrane defects and to achieve longer life.

关 键 词：钯膜 氢分离 一氧化碳甲烷化 双功能 镍催化剂 质子交换膜燃料电池 

分 类 号：O643.36[理学—物理化学]