| 摘要: | 本研究以檸檬酸溶膠凝膠法（sol-gel）製備La2NiO4、LaSrNiO4、La0.7Ce0.3SrNiO4等Pervskite oxide型觸媒，並觀察三者分解NO效能之差異。此外，亦利用非熱電漿放電技術，針對鍛燒後之La0.7Ce0.3SrNiO4觸媒進行N2或Air電漿處理，以瞭解電漿處理對於觸媒效能之影響，並針對電漿處理前後的觸媒進行相關物性分析。實驗結果顯示，La0.7Ce0.3SrNiO4觸媒具最佳NO分解率。操作參數方面，固定NO濃度1000ppm、反應溫度600－900℃、空間流速8000h-1。在無氧、900℃的條件下、，以氮氣作為載氣之NO分解率高於氬氣，所得結果分別為99.90％和49.89％；在900℃、氧氣濃度1%時，以氮氣和氬氣作為載氣之NO分解率略為下降，分別為99.12%和44.97%，表示觸媒在此含氧量下活性抑制的情形輕微，但提高含氧量至3%及6%時，NO分解率低於40%。非熱電漿改質觸媒方面，其操作參數為：氣體流量1000sccm、空間流速1241 h-1、施加電壓16.5kV、放電頻率100Hz、氣體種類為N2及Air。未經電漿改質的La0.7Ce0.3SrNiO4觸媒在900℃、氧氣濃度0%和1%時之NO分解率雖高於經電漿處理之觸媒，但提高氧氣濃度後，發現經電漿改質後的觸媒之NO分解率並未像電漿改質的觸媒急速下降，N2電漿及Air電漿觸媒在氧氣濃度3%及6%時之NO分解率分別為36.45%、17.81%及28.55%、12.27%；未經電漿改質觸媒在氧氣濃度在3%及6%時之NO分解率分別為24.66%及6.54%，顯示在較高含氧量下，電漿改質後之觸媒對氧氣有較高之容忍力。Perovskite-type oxides including La2NiO4, LaSrNiO4, and La0.7Ce0.3SrNiO4 were prepared by the citric acid complexation and used as catalysts for direct decomposition of NO. Moreover, non-thermal plasma technology was applied after calcinations of La0.7Ce0.3SrNiO4. In this study, i.e., citric acid complexation (without plasma treatment), N2-plasma-treated, and air-plasma-treated catalysts were tested for NO decomposition to understand the effect of plasma treatment on the catalytic performance. The catalysts before and after plasma treatment were characterized, respectively, to discern the effects. The activities of La2NiO4, LaSrNiO4, and La0.7Ce0.3SrNiO4 for NO decomposition were tested and the results indicate that in the same experimental parameters, La0.7Ce0.3SrNiO4 catalyst is of the highest NO decomposition with Ar, with the efficiency up to 49.89%. The inlet NO concentration was controlled at 1000 ppm, and the reaction temperature ranged from 600℃ to 900 ℃, while the space velocity was fixed at 8,000h-1. The influences of oxygen content and water vapor content on NO decomposition were also explored. In the absence of O2, NO decomposition achieved is much higher as N2 is used as carrier gas compared with Ar. With 1% oxygen content in the gas stream, NO decomposition decreased slightly to 99.12% and 44.97%, respectively, as N2 and Ar are used as the carrier gases. The results indicate that the activation of catalyst was slightly suppressed with 1% O2 content. On the other hand, NO decomposition decreases rapidly as the oxygen content is increased to 3% and 6%.Non-thermal plasma is applied to modify the performance of perovskite-type oxides catalyst. The operating parameters are as following：gas flow rate is 1000 sccm, space velocity is 1241 h-1, the applied voltage is 16.5kV, and the discharge frequency is 100 Hz with either nitrogen or air as carieer gas. At 900℃, NO decomposition achieved with La0.7Ce0.3SrNiO4 catalyst before plasma treatment as N2 is used as carrier gas is much higher than that the catalyst after plasma treatment in the presence of 0% or 1% O2, however, as the oxygen content is increased to 3% and 6%, the La0.7Ce0.3SrNiO4 catalyst before plasma treatment activity is significantly decreased to 24.66% and 6.54%, respectively, as N2 is used as the carrier gas. The results lower than the La0.7Ce0.3SrNiO4 catalyst after plasma treatment with N2 as the carrier gas. As the oxygen content is increased to 3% and 6%, the N2-plasma-treatment catalyst activity is 36.45% and 17.81%, respectively, and air-plasma-treatment catalyst activity is 28.55% and 12.27%, respectively. The results indicate that the the catalysts after plasma treatment possess strong tolerance in the presence of 3% and 6% oxygen content. |
