Pd掺杂量对有机无机杂化SiO2膜H2/CO2分离性能和水热稳定性能的影响

以1,2-二(三乙氧基硅基)乙烷(BTESE)为前驱体、PdCl₂为钯源, 制备Pd掺杂有机无机杂化SiO₂(POS)溶胶, 涂膜后在水蒸气氛围中煅烧, 制备得到POS膜。采用X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、N₂吸附-脱附和透射电子显微镜(TEM)对POS粉体的微观结构进行表征。考察了钯/硅摩尔比(n(Pd/Si)=0.1、0.5和1)对POS膜的气体分离性能与水热稳定性能的影响。结果表明: 随着Pd掺杂量的增加, POS膜的H₂渗透率逐渐增大, H₂/CO₂的理想选择性逐渐下降。经100 kPa水蒸气处理180 h后, 采用n (Pd/Si)=1制备的POS膜的H₂渗透率达到1.62× 10^-7 mol·m^-2·s^-1·Pa^-1, H₂/CO₂理想分离因子达到13.6, 表明该膜具有较好的H₂渗透性能、H₂/CO₂分离性能和水热稳定性能。

Pd Doping on H2/CO2 Separation Performance and Hydrothermal Stability of Organic-inorganic Hybrid SiO2 Membranes

Pd-doped organic-inorganic hybrid SiO₂ (POS) sols were synthesized by using 1,2-bis(triethoxysilyl) ethane (BTESE) and palladium chloride as precursors. POS membranes were fabricated via dip-coating process followed by calcination in the water vapor environment. The microstructure of POS powders was characterized by X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), N₂ adsorption-desorption, and transmission electron microscope (TEM). Effect of the molar ratio of Pd to Si (n (Pd/Si)=0.1, 0.5 and 1) on separation performance and hydrothermal stability of POS membranes was investigated. Results showed that with the increase of Pd doping amount, H₂ permeance of POS membranes increased while the permselectivity of H₂/CO₂ decreased. After exposing to 100 kPa steam atmosphere for 180 h, H₂ permeance and H₂/CO₂ permselectivity of the POS membrane prepared with n (Pd/Si) of 1 reached 1.62×10^-7 mol·m^-2·s^-1·Pa^-1 and 13.6, respectively. This result indicated that as-prepared POS membrane exhibited good H₂ permeance, H₂/CO₂ permselectivity and hydrothermal stability.