Preparation method of NOx adsorbent operated at room temperature

[0011] The invention provides a method for preparing a nitrogen oxide adsorbent with high adsorption capacity, which is characterized in that the method includes the following steps:

[0012] 1) Pretreatment of activated carbon carrier: Disperse activated carbon in a 0.1M~10M nitric acid solution with a liquid-to-solid mass ratio of 1:1~1:100. Heat to 40~90℃ under stirring and reflux, and oxidize for 5~20hr. Filter, wash and dry in the air to constant weight;

[0013] 2) Metal element loading: Dissolve soluble cerium salt and soluble transition metal salt in water, where the molar ratio of cerium element and transition metal element is between 9:1 and 5:5, and put the activated carbon prepared in step 1) into In an aqueous solution of soluble cerium salt and soluble transition metal salt, heat under stirring to gradually evaporate the solvent to dryness at the boiling point of the solvent itself, and then add any one of nitrogen, helium, and argon or a mixture of any several gases Burn in an atmosphere at 300-600°C for 2-6 hours to obtain a nitrogen oxide adsorbent with high adsorption capacity using activated carbon as a carrier.

[0014] The technical feature of the present invention is also that: the activated carbon in the method is any one or a mixture of coal-based activated carbon, wood activated carbon, pitch-based activated carbon, activated carbon fiber, phenolic resin-based activated carbon, and nutshell activated carbon; The soluble cerium salt in the method is any one of cerium (III) nitrate and cerium acetate (III) or a mixture of two in any ratio; the soluble transition metal salt in the method is manganese (II) nitrate and manganese acetate (II) ), any one of cobalt (II) nitrate, and cobalt acetate (II) or a mixture of any of them; in the method, the molar ratio of cerium element and transition metal element is 8:2-6:4; the method The loading amount of cerium element and transition metal element is 0.0001 mol to 0.0045 mol (cerium element + transition metal element)/10 g of activated carbon; the calcination temperature of the material in the method under inert gas is 350 to 450°C.

[0016] Example 1:

[0017] Add 2000g of activated carbon particles (30 mesh in size) to 200kg of 0.1M nitric acid, oxidize at 90°C for 5hrs under stirring and reflux, filter the activated carbon, wash it thoroughly, and dry it in the air to a constant weight;

[0018] Dissolve 0.002mol cobalt(II) nitrate and 0.018mol cerium(III) nitrate in 500mL water, add the above activated carbon, and heat to 100℃ with stirring to evaporate and evaporate to dryness (the loading amount of Ce+Co is 0.0001mol/10g activated carbon ), and then burned in a muffle furnace under a nitrogen atmosphere at 300°C for 6 hours to obtain an adsorbent capable of absorbing nitrogen oxides at room temperature, which can treat more than 100,000 bed volumes of air containing 1ppm NOx at room temperature.

[0019] Example 2:

[0020] Add 333.33g of activated carbon to 333.33g of 10M nitric acid, oxidize at 40°C for 20hr under stirring and reflux, filter the activated carbon, wash it thoroughly, and dry it in the air to a constant weight;

[0021] Dissolve 0.05mol manganese (II) nitrate and 0.1mol cerium (III) nitrate in 200mL water, add the above activated carbon, stir and heat to volatilize and evaporate to dryness (the loading amount of Ce+Mn is 0.0045mol/10g activated carbon), and then Burn in a muffle furnace under a nitrogen atmosphere at 600°C for 2 hours to obtain an adsorbent capable of absorbing nitrogen oxides at room temperature, which can treat more than 100,000 bed volumes of air containing 1ppm NOx at room temperature.