金属阳离子对高硅分子筛催化氧化NO的影响

采用离子交换法制备了Na-、K-、Co-、NiZSM-5分子筛催化剂.测试了它们催化氧化NO的性能并通过XRD、BET、ICP-MS和Py-IR等表征，结果表明，CoZSM-5分子筛对NO催化氧化具有最高的活性，氧化率达到47%，主要是引入Co离子的ZSM-5表面酸性最适宜NO氧化.同时，在湿度100%条件下，考察了氧气浓度（5%~20%），空速与二氧化硫浓度（0~200×10^-6）等对CoZSM-5分子筛催化氧化NO性能的影响.实验结果表明，在30℃、空速14400h^-1和相对湿度100%条件下，SO₂浓度在200×10^-6以下对催化氧化NO基本无影响.56h催化剂稳定性实验结果表明，在30℃、NO进口浓度600×10^-6、空速18000h^-1和饱和水汽（RH：100%）条件下，CoZSM-5分子筛催化剂对NO的氧化率可维持在40%左右.因此CoZSM-5分子筛催化剂具有良好的NO氧化稳定性、抗水性和一定的抗硫性.

Influence of metal cations on catalytic oxidation of NO over high-silica zeolites

A series of HZSM-5、Na-、K-、Co-、NiZSM-5catalysts were prepared by ion exchanged method and characterized by XRD、BET、ICP-MS and Py-IR. Their catalytic activities were investigated in the catalytic oxidation of NO. Results showed that the CoZSM-5possessed moderate surface acidity and was the most beneficial for NO oxidation, then performed highest activity to 47%. Meanwhile, the influences of space velocity, O₂ concentration (5%~20%) and SO₂ concentration (0~200×10^-6) were investigated, under 600×10^-6 inlet NO concentration and 100% RH. Experimental results revealed that SO₂ concentration (below 200×10^-6) had little impact on NO oxidation reaction and the NO oxidation conversion was maintained at 40% in 56h lifetime test, under 30℃、600ppm NO、18000h^-1 SV and 100% RH.