Preparation method and application of Ce-doped epsilon-MnO2 nano particles

Abstract

The invention discloses a preparation method and application of Ce-doped epsilon-MnO2 nanoparticles, and the preparation method comprises the following steps: step 1, dissolving ceric ammonium nitrateand MnSO4. H2O in an inorganic acid solution, and uniformly stirring, the molar ratio of ceric ammonium nitrate to MnSO4. H2O being (1: 2)-(3: 1); step 2, transferring the solution treated in the step 1 into a microwave hydrothermal parallel synthesizer for synthesis reaction, cooling to room temperature after the reaction is finished, and filtering, washing and drying the obtained product to obtain amorphous MnO2; and step 3, calcining the amorphous MnO2 in an air atmosphere so as to obtain the Ce-doped epsilon-MnO2 nano particles. The preparation method is simple in process, easily available in raw materials, high in yield and good in repeatability and shows good medium and low temperature catalytic activity and a relatively wide temperature window in selective catalytic reduction (SCR)and is high in conversion rate.

Description

technical field [0001] The invention relates to the field of synthesis of inorganic nanomaterials, in particular to a Ce-doped ε-MnO 2 Preparation methods and applications of nanoparticles. Background technique [0002] Manganese dioxide (MnO 2 ) is an important inorganic functional material, which is widely used in environmental protection, energy, and chemical industries. MnO 2 Available in multiple crystal forms, including δ-MnO 2 , α-MnO 2 , ε-MnO 2 and β-MnO 2 etc., among them, ε-MnO 2 It is a twin structure formed by the alternate growth of 1×1 and 1×2 manganese-oxygen octahedral tunnel structures. ε-MnO 2 With good redox performance, it can be used as a catalyst in environmental catalysis, synthetic catalysis and other fields. According to the existing literature, ε-MnO can be prepared by hydrothermal synthesis, co-precipitation and other methods. 2 Material. For example, Ding et al. (Advanced Functional Materials, 2006,16,549-555) used NaClO 4 As an oxid...

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Problems solved by technology

ε-MnO prepared by the above synthesis method 2 The material has a large particle size, and the particle diameter is greater than 1 μm, which makes ε-MnO 2 The specific surface area of ​​the material is low, resulting in its catalytic activity is still not ideal

In addition, the ε-MnO synthesized by the solution system 2 The thermal stability of the material is poor, and it is easy to cause ε-MnO 2 Structural collapse and phase transition into less active β-MnO occur during high-temperature catalytic reactions 2

The above problems make ε-MnO 2 The material exhibits general thermocatalytic activity and poor stability, which greatly limits the ε-MnO 2 Application of materials in the field of catalysis

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