Microporous carbon aerogel and preparation method thereof

Abstract

The invention relates to microporous carbon aerogel and a preparation method thereof. The microporous carbon aerogel is prepared by adding mixed eutectic molten salt composed of LiNO3, KNO3 and K2SO4 in a step of preparing organic wet gel; parameters include that specific surface area is 850-1350m2 / g, pore size distribution is 1-2nm, pore volume is 0.38-0.43cm3 / g, and adsorption amount of CO2 at normal temperature and normal pressure is 3.2-3.8mmol / g. The microporous carbon aerogel prepared by the method is high in specific surface area, narrow in pore size distribution range, large in pore volume and high in ability of adsorbing carbon dioxide. The preparation method is simple in steps, convenient to operate, low in production cost, short in process time and environment-friendly.

Description

technical field

[0001] The invention relates to a microporous carbon aerogel and a preparation method thereof, belonging to the field of carbon aerogel preparation. Background technique

[0002] Carbon aerogel is a new type of lightweight porous material, which is widely used as catalyst carrier, Hydrogen storage materials, adsorption materials, and electrode materials for supercapacitors or lithium-ion batteries, etc., are conducive to solving the energy crisis and environmental pollution problems in today's society and have become research hotspots.

[0003] Carbon aerogels have different performance requirements due to their different application fields, so the preparation methods are different. for CO 2 For carbon aerogels as gas adsorbents, there are certain requirements for their pore size. CN201611110955.8 discloses a method for preparing carbon aerogels, which uses resorcinol and formaldehyde as raw materials, organic amines as catalysts, water as a solvent, stirr...

Examples

Embodiment 1

[0058] Step 1: Organic Wet Gel Preparation

[0059] Mix polyhydroxybenzene and formaldehyde at a molar ratio of 1:2, add deionized water to prepare a reaction solution with a mass fraction of 40%, and then add 38% LiNO 3 , 46% KNO 3 and 16%K 2 SO 4 The mixed eutectic salt, the addition of the mixed eutectic salt is 20% of the total mass of polyhydroxybenzene and formaldehyde, the reaction solution is evenly mixed and then sealed, and kept at 50°C for full reaction for 3 days to obtain resorcinol- Phloroglucinol-formaldehyde organic wet gel, the polyhydroxybenzene is a mixture of phloroglucinol and resorcinol in a molar ratio of 7:1;

[0060] Step 2: Freeze drying

[0061] Put the organic wet gel prepared in step 1 directly into a freeze-drying box, and dry it at -80±5°C for one day to obtain an organic aerogel;

[0062] Step 3: High temperature carbonization

[0063] The organic airgel obtained in step 2 was carbonized under vacuum conditions, and N was continuously fed ...

Embodiment 2

[0068] Step 1: Organic Wet Gel Preparation

[0069] Mix polyhydroxybenzene and formaldehyde at a molar ratio of 1:2, add deionized water to prepare a reaction solution with a mass fraction of 40%, and then add 36% LiNO 3 , 52% KNO 3 and 12%K 2 SO 4 The mixed eutectic salt, the addition of the mixed eutectic salt is 20% of the total mass of polyhydroxybenzene and formaldehyde, the reaction solution is evenly mixed and then sealed, and kept at 50°C for full reaction for 3 days to obtain resorcinol- Phloroglucinol-formaldehyde organic wet gel, the polyhydroxybenzene is a mixture of phloroglucinol and resorcinol in a molar ratio of 7:1;

[0070] Step 2: Freeze drying

[0071] Put the organic wet gel prepared in step 1 directly into a freeze-drying box, and dry it at -80±5°C for one day to obtain an organic aerogel;

[0072] Step 3: High temperature carbonization

[0073] The organic airgel obtained in step 2 was carbonized under vacuum conditions, and N was continuously fed ...

Embodiment 3

[0078] Step 1: Organic Wet Gel Preparation

[0079] Mix polyhydroxybenzene and formaldehyde at a molar ratio of 1:2, add deionized water to prepare a reaction solution with a mass fraction of 40%, and then add 42% LiNO 3 , 46% KNO 3 and 12%K 2 SO 4 The mixed eutectic salt, the addition of the mixed eutectic salt is 20% of the total mass of polyhydroxybenzene and formaldehyde, the reaction solution is evenly mixed and then sealed, and kept at 50°C for full reaction for 3 days to obtain resorcinol- Phloroglucinol-formaldehyde organic wet gel, the polyhydroxybenzene is a mixture of phloroglucinol and resorcinol in a molar ratio of 7:1;

[0080] Step 2: Freeze drying

[0081] Put the organic wet gel prepared in step 1 directly into a freeze-drying box, and dry it at -80±5°C for one day to obtain an organic aerogel;

[0082] Step 3: High temperature carbonization

[0083] The organic airgel obtained in step 2 was carbonized under vacuum conditions, and N was continuously fed ...

technical field

[0001] The invention relates to a microporous carbon aerogel and a preparation method thereof, belonging to the field of carbon aerogel preparation. Background technique

[0002] Carbon aerogel is a new type of lightweight porous material, which is widely used as catalyst carrier, Hydrogen storage materials, adsorption materials, and electrode materials for supercapacitors or lithium-ion batteries, etc., are conducive to solving the energy crisis and environmental pollution problems in today's society and have become research hotspots.

[0003] Carbon aerogels have different performance requirements due to their different application fields, so the preparation methods are different. for CO 2 For carbon aerogels as gas adsorbents, there are certain requirements for their pore size. CN201611110955.8 discloses a method for preparing carbon aerogels, which uses resorcinol and formaldehyde as raw materials, organic amines as catalysts, water as a solvent, stirr...

Examples

Embodiment 1

[0058] Step 1: Organic Wet Gel Preparation

[0059] Mix polyhydroxybenzene and formaldehyde at a molar ratio of 1:2, add deionized water to prepare a reaction solution with a mass fraction of 40%, and then add 38% LiNO 3 , 46% KNO 3 and 16%K 2 SO 4 The mixed eutectic salt, the addition of the mixed eutectic salt is 20% of the total mass of polyhydroxybenzene and formaldehyde, the reaction solution is evenly mixed and then sealed, and kept at 50°C for full reaction for 3 days to obtain resorcinol- Phloroglucinol-formaldehyde organic wet gel, the polyhydroxybenzene is a mixture of phloroglucinol and resorcinol in a molar ratio of 7:1;

[0060] Step 2: Freeze drying

[0061] Put the organic wet gel prepared in step 1 directly into a freeze-drying box, and dry it at -80±5°C for one day to obtain an organic aerogel;

[0062] Step 3: High temperature carbonization

[0063] The organic airgel obtained in step 2 was carbonized under vacuum conditions, and N was continuously fed ...

Embodiment 2

[0068] Step 1: Organic Wet Gel Preparation

[0069] Mix polyhydroxybenzene and formaldehyde at a molar ratio of 1:2, add deionized water to prepare a reaction solution with a mass fraction of 40%, and then add 36% LiNO 3 , 52% KNO 3 and 12%K 2 SO 4 The mixed eutectic salt, the addition of the mixed eutectic salt is 20% of the total mass of polyhydroxybenzene and formaldehyde, the reaction solution is evenly mixed and then sealed, and kept at 50°C for full reaction for 3 days to obtain resorcinol- Phloroglucinol-formaldehyde organic wet gel, the polyhydroxybenzene is a mixture of phloroglucinol and resorcinol in a molar ratio of 7:1;

[0070] Step 2: Freeze drying

[0071] Put the organic wet gel prepared in step 1 directly into a freeze-drying box, and dry it at -80±5°C for one day to obtain an organic aerogel;

[0072] Step 3: High temperature carbonization

[0073] The organic airgel obtained in step 2 was carbonized under vacuum conditions, and N was continuously fed ...

Embodiment 3

[0078] Step 1: Organic Wet Gel Preparation

[0079] Mix polyhydroxybenzene and formaldehyde at a molar ratio of 1:2, add deionized water to prepare a reaction solution with a mass fraction of 40%, and then add 42% LiNO 3 , 46% KNO 3 and 12%K 2 SO 4 The mixed eutectic salt, the addition of the mixed eutectic salt is 20% of the total mass of polyhydroxybenzene and formaldehyde, the reaction solution is evenly mixed and then sealed, and kept at 50°C for full reaction for 3 days to obtain resorcinol- Phloroglucinol-formaldehyde organic wet gel, the polyhydroxybenzene is a mixture of phloroglucinol and resorcinol in a molar ratio of 7:1;

[0080] Step 2: Freeze drying

[0081] Put the organic wet gel prepared in step 1 directly into a freeze-drying box, and dry it at -80±5°C for one day to obtain an organic aerogel;

[0082] Step 3: High temperature carbonization

[0083] The organic airgel obtained in step 2 was carbonized under vacuum conditions, and N was continuously fed ...

Images