摘要
In recent years, SF6 has been widely used in the electrical industry. The amount of SF6 waste gas produced by the corresponding gas insulated equipment is increasing year by year. However, SF6 has high global warming potential and long atmospheric life. Proper treatment of SF6 waste gas is particularly important for environmental protection. Thermal degradation can effectively eliminate the greenhouse effect caused by direct emission of SF6. In this paper, AlPO4, Zr-3(PO4)(4) and CePO4 were used as catalysts to degrade SF6/air mixture gas (The concentration of SF6 is 15%) at 800 degrees C. The concentration of SF6 gas was detected by gas chromatography (GC), and the gas decomposition products of SF6 were detected by gas chromatography mass spectrometry (GCMS) and fourier transform infrared spectroscopy (FTIR). The surface morphology and composition of the catalyst were analyzed by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The results show that the three kinds of metal phosphates can promote the decomposition of SF6 gas, among which CePO4 had the best catalytic degradation effect, and the degradation rate of SF6 reached 84.7% in 12 h. The main products of SF6 gas thermal catalytic degradation include SF4, S2F10, SO2F2, SOF2, SiF4 and SO2 gas, etc. SEM scanning image shows that there were some objects adsorbed on the surface of CePO4 catalyst after the experiment. XPS spectra showed that Si and F elements were added to the catalyst. According to the binding energy, SiF4 was adsorbed on the catalyst. After the experiment, CeF3 was produced by CePO4 catalyst. Different catalysts have their own selectivity to the decomposition products of SF6, which is convenient for the treatment of products, and it is of great significance to eliminate the greenhouse effect caused by the waste gas of SF6.