Effect of DMF addition on the phase-chemical structure of Pd-doped methyl-modified silica membrane materials calcined in air atmosphere

ABSTRACT

Pd-doped methyl-modified SiO₂ membrane materials were prepared by sol-gel technique with tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES) as silicon precursors, PdCl₂ as palladium source. N, N-dimethylformamide (DMF) was used as a drying control chemical additive (DCCA). The samples were characterized by X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and thermogravimetric (TG)-differential thermogravimetric (DTG) measurement. The effect of DMF addition on the phase and chemical structures of Pd-doped SiO₂ membrane materials calcined at 350°C was discussed. The results showed that the diffraction peaks of metallic Pd⁰ and PdO appeared in the XRD curve of Pd-doped SiO₂ membrane material without DMF, while only the metallic Pd⁰ diffraction peak can be explicitly observed in the Pd-doped SiO₂ membrane material with DMF. DMF has no significant influence on the chemical structure of Pd-doped SiO₂ membrane materials but can delay the oxidation of metallic Pd⁰ to PdO in the air.

KEYWORDS:

• Sol-gel method
• DMF addition
• Pd-doped silica membrane
• air atmosphere

Additional information

Funding

The authors acknowledge the financial assistance from the National Natural and Science Foundation Council of China 21573171 and 21603169, Shaanxi Province Key Research and Development Plan of China 2017GY-121 and Shaanxi Province Industrial Science and Technology Research Projects of China 2015GY168.