Mn/Ce改性菱铁矿催化剂在SCR脱硝反应中的特性研究

富含过渡元素的菱铁矿是用于制备选择性催化还原（SCR）脱硝催化剂的理想材料。在本研究中，对菱铁矿掺杂了Mn和Ce，并研究了Mn-Ce共掺杂改性菱铁矿在NH₃-SCR反应中去除NO_x的活性。结果表明，经过450℃煅烧后菱铁矿的主要成分FeCO₃能够转化为Fe₂O₃。菱铁矿掺杂Mn和Ce后能够提高比表面积和表面酸度，降低硫酸铵盐在催化剂表面上的热稳定性。因此，Mn-Ce共掺杂改性菱铁矿催化剂表现出较高的SCR脱硝活性和抗硫性。3% Mn1% Ce-菱铁矿催化剂在脱硝效率高于90%的温度窗口能够拓宽至180-300℃，同时在引入SO₂ 7.5 h后该催化剂的脱硝效率仍高于75%。

Performance of Mn-Ce co-doped siderite catalysts in the selective catalytic reduction of NOx by NH3

Siderite, rich in the transition elements, is an idea material to prepare the catalysts for the selective catalytic reduction (SCR) of NO_x by NH₃. In this work, siderite was doped with Mn and Ce and the performance of Mn-Ce co-doped siderite catalysts in the removal of NO_x (de-NO_x) by SCR with NH₃ was then investigated. The results illustrate that FeCO₃ as the main component of siderite can be converted into Fe₂O₃ by calcination at 450℃. The doping of siderite with Mn and Ce can enhance the surface area and acidity of siderite and reduce the thermal stability of ammonium sulfate formed on the catalyst surface. As a result, the Mn-Ce co-doped siderite catalysts exhibit high efficiency in the de-NO_x by SCR and high resistance against sulfur. Over the 3%Mn1%Ce-siderite catalyst, high NO_x conversion (>90%) is achieved in the temperature window of 180-300℃; moreover, the NO_x conversion remains above 75% even after introducing SO₂ for 7.5 h.