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研究了HZSM-5分子筛孔径对其在等离子体场内催化降解甲苯的影响.采用化学液相沉积法对HZSM-5分子筛进行改性,利用XRD、氮气吸附脱附等方法表征样品的骨架结构和表面性质,并用择形吸附实验对样品孔径进行表征.同时,评价了HZSM-5分子筛体系中降解甲苯的性能,研究了分子筛吸附甲苯性能及臭氧的产量,并采用飞行时间质谱(TOF-MS)和气相色谱-质谱联用仪(GC-MS)分析了反应产生的有机副产物.结果表明:液相沉积法成功调控了HZSM-5孔径,样品孔径随沉积剂用量增加而减小;同时,样品均具有相同的MFI骨架结构,比表面积和孔容相差不大.HZSM-5的孔径尺寸对甲苯去除率影响不大,但对碳平衡有影响,孔径越大,碳平衡越好.孔径较大的HZSM-5分子筛对甲苯具有更大的吸附速率和吸附容量,同时更多臭氧参与反应,生成·OH和O·,促进甲苯深度氧化,减少副产物,提高碳平衡.
The effect of HZSM-5 molecular sieve pore size on the catalytic degradation of toluene in the plasma field was studied.The chemical structure of HZSM-5 molecular sieve was modified by chemical liquid deposition method, the structure of the sample was characterized by XRD, nitrogen adsorption and desorption The surface properties of the samples were characterized by shape-selective adsorption. The performance of HZSM-5 molecular sieve system for toluene degradation was also evaluated. The performance of toluene adsorption and ozone production by molecular sieve were studied. The time-of-flight mass spectrometry (TOF- (GC-MS) and gas chromatography-mass spectrometry (GC-MS). The results showed that the pore size of HZSM-5 was successfully controlled by liquid-phase deposition and the pore size decreased with the increase of the amount of deposition agent. The samples have the same MFI framework structure, the specific surface area and pore volume is not much difference.HZSM-5 pore size has little effect on toluene removal rate, but has an impact on the carbon balance, the larger the pore size, the better the carbon balance. Large HZSM-5 zeolite has larger adsorption rate and adsorption capacity for toluene. At the same time, more ozone participates in the reaction to generate · OH and O ·, promote deep oxidation of toluene, reduce by-products and increase carbon balance.