溶胶-凝胶法载银SiO2杂化膜的制备及性能研究

采用溶胶-凝胶法,在甲基化改性的SiO2溶胶中掺杂硝酸银,制备Ag/M-SiO2杂化膜。通过XRD、XPS、紫外-可见吸收谱、N2吸附-脱附以及气体渗透性能测试等方法,考察了银掺杂对杂化膜结构和性能的影响。结果表明,Ag/M-SiO2膜中的银元素完全为纳米金属银,具有面心立方结构。金属银的掺杂对Ag/M-SiO2膜的化学结构基本没有影响,但使其孔径和总孔体积略微增大。与未载银的SiO2膜相比,Ag/M-SiO2膜具有更大的H2渗透速率和更好的H2/CO2选择性。金属银的引入增强了H2的表面扩散作用,促进了H2在膜中的传递,提高了SiO2膜的水汽稳定性。

Preparation and Properties of Silver-doped Silica Hybrid Membranes by Sol-gel Method

The silver-doped methyl-modified hybrid silica(Ag/M-SiO2) membranes were prepared using the sol-gel method by adding AgNO3 solution to a methyl-modified silica sol.The influence of Ag-doping on the structure and properties of hybrid silica membranes was investigated by using XRD,XPS,UV-visible absorption spectra,N2 adsorption-desorption measurements and gas permeance experiments.The results show that the silver element in the Ag/M-SiO2 membranes exists in the metallic silver with a face centered cubic lattice.The doping of silver nanoparticles nearly has no influence on the chemical structure of the methyl-modified silica membranes,but can make the mean pore size and total pore volume slightly increase.Compared with the methyl-modified silica membranes without silver-doping,the H2 permeance and H2/CO2 permselectivities of Ag/M-SiO2 membranes are greater.The introduction of metallic silver facilitates the transport of H2 in silica membranes and improves the steam stability of silica membranes.