镍掺杂SiO2膜的制备及CH4／CO2气体分离性能

Preparation of Nickel-Doped Silica Films and Gas Separation Performance for CH_4/CO_2

以正硅酸乙酯(TEOS)为前驱体,六水合硝酸镍(Ni(NO3)2·6H2O)为镍源,采用溶胶--凝胶法制备镍掺杂SiO2膜。研究了水用量及镍含量对镍掺杂SiO2膜的结构及形貌的影响,并对其进行CH4、CO2气体渗透性能测试。结果表明:水酯比为5.5时,制备的10%Ni掺杂SiO2膜具有良好的微孔结构,且孔径约为1.16nm,孔隙率为64.9%。一部分Ni元素以Ni和NiO晶体形式填充于SiO2孔道内,另一部分以Si—O—Ni形式进入SiO2骨架。Ni掺杂SiO2膜在84h内能够保持良好的气体渗透性能,表现出比纯SiO2膜更好的水热稳定性。CH4和CO2的气体渗透通量分别为1.56×10--7和0.64×10--7 mol/(m2·s·Pa),CH4/CO2气体分离因子达到2.43。

Ni-doped SiO2 films were prepared by a sol-gel method with tetraethylorthosilicate （TEOS） as a precursor and Ni（NOa ）2 · 6 H20 as a nickel source. The effects of water consumption and nickel content on the structure and morphology of the films were investigated, and the CH4/COs gas separation performance was analyzed. The results indicate that 10% Ni- doped SiO2 films prepared in a ratio of water to TEOS of 5.5 possess a microporous structure, the pore size is 1.16 nm and the porosity is 64. 9%. A certain amount of Ni element in the crystal forms of Ni and NiO was filled into the SiO2 pores, and other amount of Ni element in the form of Si--O---Ni bond was filled into the SiO2 matriK The Ni-doped SiO2 films have a superior gas permeation in 84 h, showing a better hydrothermal stability, compared to the pure SiOz films. The permeation flux of CH4 and CO2 gas are 1.56 ×10-7 and 0.64 × 10-7 mol/（m2· s·Pa）, respectively, and the CH4/CO2 separation factor is 2.43.