Fe/Ga2O3-Al2O3催化甲烷还原NO的性能  

Performance of Fe/Ga203-Al203 catalysts on methane selective catalysis and NO reduction

作　　者：林睿 苏亚欣[1] 程江浩 张显威 温妮妮 邓文义[1] 周皞 赵兵涛[3] LIN Rui;SU Yaxin;CHENG Jianghao;ZHANG Xianwei;WEN Nini;DENG Wenyi;ZHOU Hao;ZHAO Bingtao(School of Environmental Science and Engineering,Donghua University,Shanghai 201620,China;School of Itelligent Manufacturing,Changzhou Vocational Institute of Engineering,Changzhou 213164,China;School of Energy and Power Engineering,University of Shanghai Science and Technology,Shanghai 200093,China)

机构地区：[1]东华大学环境科学与工程学院,上海201620 [2]常州工程技术学院智能制造学院,常州213164 [3]上海理工大学能源与动力工程学院,上海200093

出　　处：《环境工程学报》2020年第6期1592-1604,共13页Chinese Journal of Environmental Engineering

基　　金：上海市自然科学基金资助项目(19ZR1400700,17ZR1419300);江苏省自然科学基金资助项目(BK20181161);中央高校基本科研业务费(2232019D3-24)。

摘　　要：以甲烷为还原剂的选择性催化脱硝技术(SCR-CH4)是一种很有潜力的新的脱硝方法,但催化剂的催化活性比较低。为了提高催化剂的活性以及抗水能力,可使用Fe对Al2O3负载的Ga2O3催化剂进行改性。采用共沉淀法,制备了xFe/Ga2O3-Al2O3催化剂,在固定床反应器中测试其选择性催化CH4还原NO的性能。使用XRD、N2吸附脱附、XPS、H2-TPR、Py-IR等方法进行表征。结果表明:经过Fe改性后的催化剂提高了中高温的催化活性,提高了催化剂的N2选择性,并改善了催化剂的抗水特性;5Fe/Ga2O3-Al2O3催化剂在500℃、富氧条件下,达到76%的NO转化率和100%的N2选择性;在5%水蒸气条件下,5Fe/Ga2O3-Al2O3在500℃仍保持60%以上的NO转化率。N2吸附脱附结果显示,引入Fe后,催化剂保持了原有比表面积,并且大大增加了催化剂孔径,可提高催化剂抗水能力。XPS与UV-vis显示,5Fe/Ga2O3-Al2O3具有高含量的游离态Fe3+,可提高催化剂的中高温活性。H2-TPR结果显示,Fe的引入提高了催化剂氧化还原能力,增强了原有Ga2O3-Al2O3中高温的还原活性。Py-FT-IR结果显示,催化剂表面同时存在Lewis酸和Br?nsted酸,铁的引入增加了催化剂表面的Lewis酸量。因此,Fe修饰Ga2O3-Al2O3是提高Ga2O3-Al2O3催化剂的SCR-CH4脱硝性能的有效方法。The selective catalytic denitration with methane reductant(SCR-CH4) is a very promising alternative method, however, the current reported catalysts showed low catalytic reactivity for SCR-CH4. In order to improve the catalytic reactivity and the water resistance of the catalysts, Fe was used to modify the Ga2O3 catalysts supported on Al2O3. The x Fe/Ga2O3-Al2O3 catalysts were prepared by co-precipitation method, and their catalytic performance on methane selective catalysis and NO reduction was tested in a fixed bed reactor.XRD, N2 adsorption desorption, XPS, H2-TPR, Py-IR, etc were used to characterize the x Fe/Ga2O3-Al2O3 catalysts. The results showed that the catalysts modified by Fe improved the catalytic activity at medium and high temperature, their N2 selectivity, and their tolerance for water presented in the feed gas. At 500 ℃ and oxygen-rich conditions, the 5 Fe/Ga2O3-Al2O3 catalyst could achieve 76% NO conversation and 100% N2 selectivity. Under 5% water vapor conditions, 5 Fe/Ga2O3-Al2O3 still maintained over 60% NO conversation at500 ℃. The results of N2adsorption and desorption showed that the original specific surface area was maintained for the Fe-doped catalysts, and their pore size increased significantly, which improved their waterresistance ability. XPS and UV-vis detection showed that 5 Fe/Ga2O3-Al2O3 had a high content of free Fe3+,which contributed to the medium-high temperature activity. The H2-TPR results showed that the introduction of Fe elevated the redox capacity of the catalysts and enhanced the medium-high temperature reduction activity of the original Ga2O3-Al2O3. Py-FT-IR results showed that both Lewis acid and Br?nsted acid existed on the surface of the catalysts, and the introduction of Fe raised the content of the Lewis acid. Therefore, Fe modification of Ga2O3-Al2O3 is an effective method to improve the performance of SCR-CH4 of Ga2O3-Al2O3.

关 键 词：选择性催化还原 NO CH4 Fe/Ga2O3-Al2O3催化剂 

分 类 号：X511[环境科学与工程—环境工程]