CAJ | 학술논문

通过水热法合成了两种具有不同形貌的α-Fe2O3纳米棒和纳米立方体,并探索了它们的中温NH3选择性化还原(NH3-SCR)NO的活性.NH3-SCR测试表明α-Fe2O3纳米棒具有更高的催化活性.X射线粉末衍射(XRD)、场发射扫描电镜(FE-SEM)和高分辨透射电镜(HRTEM)结构分析表明:α-Fe2O3纳米棒暴露有高表面能的{110}活性面,而纳米立方体暴露的主要是低表面能的{012}晶面.H2程序升温还原(H2-TPR)和NO程序升温脱附(NO-TPD)结果证明纳米棒比纳米立方体具有更高的氧化还原性能.因此,α-Fe2O3纳米棒由于暴露高表面能的活性面具有比纳米立方体更高的NH3-SCR性能.
통과수열법합성료량충구유불동형모적α-Fe2O3납미봉화납미립방체,병탐색료타문적중온NH3선택성화환원(NH3-SCR)NO적활성.NH3-SCR측시표명α-Fe2O3납미봉구유경고적최화활성.X사선분말연사(XRD)、장발사소묘전경(FE-SEM)화고분변투사전경(HRTEM)결구분석표명:α-Fe2O3납미봉폭로유고표면능적{110}활성면,이납미립방체폭로적주요시저표면능적{012}정면.H2정서승온환원(H2-TPR)화NO정서승온탈부(NO-TPD)결과증명납미봉비납미립방체구유경고적양화환원성능.인차,α-Fe2O3납미봉유우폭로고표면능적활성면구유비납미립방체경고적NH3-SCR성능.
α-Fe2O3samples with nanocube and nanorod morphologies were synthesized by a simple hydrothermal route.The samples were characterized by powder X-ray diffraction (XRD),field emission scanning electron microscopy (FE-SEM),high-resolution transmission electron microscopy (HRTEM),temperature- programmed reduction by H2 (H2-TPR),and temperature-programmed desorption of NO (NO-TPD),and tested for the selective catalytic reduction with NH3 (NH3-SCR) of NO at moderate temperatures.The α-Fe2O3 nanocubes possessed predominantly exposed {012} faces with low surface energy,while the nanorods also had some high energy {110} faces exposed.The catalytic activities of the α-Fe2O3 samples were predominantly governed by their surface structures.The nanorods showed much higher activity than the nanocubes under identical conditions,consistent with the better redox properties of the nanorods as confirmed by H2-TPR and NO-TPD measurements.Therefore,α-Fe2O3 nanorods with exposed high energy faces have much higher activity for NH3-SCR than nanocubes with exposed low energy faces under identical reaction conditions.