摘要
高压脉冲放电协同催化剂技术是目前最具有前景的去除NO_x的方法之一,本文以氮氧化物为处理对象,通过脉冲放电协同LaMn_(1-x)Fe_xO_3钙钛矿型催化剂去除NO_x.采用柠檬酸-EDTA溶胶凝胶法制备LaMnO_3钙钛矿催化剂,对该催化剂掺杂Fe元素,改变催化剂制备时的焙烧温度,探究催化剂协同脉冲放电在不同反应温度、催化剂投加量等因素下对NO转化、NO_2生成和NO_x的去除效果的影响,从而达到提高氮氧化物的去除率、降低能耗等目的.同时结合XRD、SEM、BET等表征手段对催化剂进行表征.结果表明,在催化剂LaMn_(1-x)Fe_xO_3中,随着Fe掺杂比的增加,NO转化率出现先增大后逐渐减小的趋势;随着催化剂的焙烧温度增加,NO转化率出现逐渐减小的趋势;随着催化剂投加量的增加,NO_x去除率不断增大后趋于稳定.在放电频率为30 Hz、脉冲电压为30 kV、Fe的掺杂比为0.3、焙烧温度为700℃、投加量为1.6 g、反应温度为300℃的条件下,NO_x的去除率为62.15%.
High-voltage pulsed discharge synergistic catalyst technology is one of the most promising NO_x removal methods at present. The object of treatment in this paper was NO_x, which was removed by a pulsed discharge in conjunction with a perovskite-type catalyst. A citric acid-EDTA Sol-Gel method was employed to prepare LaMnO_3 perovskite catalyst. By mixing Fe with the catalyst and by changing the calcination temperatures in the process of catalyst preparation, the effects of the catalyst-co-pulsed discharge on NO conversion, NO_2 generation, and NO_x removal efficiency under different sets of conditions such as reaction temperatures, catalyst doping amount were analyzed. XRD and SEM were used to characterize the catalysts. The results showed that with increasing amount of Fe added in the catalyst LaMn_(1-x)Fe_xO_3, the NO conversion first increased and then gradually went down. With the increase of calcination temperature, the NO conversion rate gradually decreased. With increasing dosage of the catalyst, the NO_x removal rate increased and then stabilized. When setting discharge frequency to be 30 Hz, pulse voltage 30 kV, Fe doping amount 0.3, calcination temperature 700 ℃, dosage of catalyst 1.6 g, and reaction temperature 300 ℃, the highest NO_x removal rate of 62.15% was reached.
引文
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