Template-free synthesis of mesoporous X–Mn (X = Co, Ni, Zn) bimetal oxides and catalytic application in the room temperature removal of low-concentration NO
Template-free synthesis of mesoporous X–Mn (X = Co, Ni, Zn) bimetal oxides and catalytic application in the room temperature removal of low-concentration NO
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DOI：
10.1039/c3ta10971b
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发表时间：
2013-08
影响因子：
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通讯作者：
Z. Shu;Weiming Huang;Zile Hua;Lingxia Zhang;Xiangzhi Cui;Yu Chen;Hangrong Chen;Chenyang Wei
中科院分区：
文献类型：
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作者：
Z. Shu;Weiming Huang;Zile Hua;Lingxia Zhang;Xiangzhi Cui;Yu Chen;Hangrong Chen;Chenyang Wei
以自制的单相草酸盐为原料，采用无模板法合成了具有良好介孔结构和高比表面积的三种锰基氧化物（Co-Mn、Ni-Mn和Zn-Mn氧化物）。这些具有可调成分（尖晶石锰酸盐）和介孔结构的氧化物首次应用于室温催化去除低浓度（10 ppm）NO，这是公路隧道和室内公园中的一种污染物。与相应的单金属氧化物相比，它们在NO去除方面表现出显著增强的效率（MnOx，Co 3 O 4，NiO，ZnO），并且在120 000 mL g-1 h-1的非常高的空速下在长达1.8 h内实现完全转化，这被认为不仅是尖晶石锰酸盐的结果，而且是非晶Co中的氧空位的结果（或Ni，Zn）掺杂的MnOx骨架。NO被催化氧化成NO2，然后通过形成亚硝酸盐和硝酸盐物种固定在氧化物中。
Three types of Mn-based bimetal oxides (Co–Mn, Ni–Mn and Zn–Mn oxides) with well-defined mesoporosities and high specific surface areas were facilely synthesized by a template-free strategy of decomposing self-made single-phase bimetal oxalate. These bimetal oxides, featuring tunable compositions (spinel manganates) and a mesoporous structure, were applied for the first time in the room temperature catalytic removal of low-concentration (10 ppm) NO, a concerning pollutant in road tunnels and indoor parks. They demonstrated substantially enhanced efficiencies in NO removal as compared with corresponding single-metal oxides (MnOx, Co3O4, NiO, ZnO), and complete conversion in up to 1.8 h at an extraordinarily high space velocity of 120 000 mL g−1 h−1 was achieved, which was proposed to be a result of not only the spinel manganates but also the oxygen vacancies in the amorphous Co (or Ni, Zn)-doped MnOx framework. NO was revealed to be catalytically oxidized into NO2 and then fixed in the bimetal oxides by forming nitrite and nitrate species.