阅读说明：本技术 新型钌基自支撑电催化材料及其制备方法和在电催化氮气还原产氨中的应用 (Novel ruthenium-based self-supporting electro-catalytic material, preparation method thereof and application thereof in electro-catalytic nitrogen reduction for producing ammonia ) 是由 孙颖 马天翼 邓子昭 李慧 王宇 黄子航 赵钦 孙晓东 冯大明 于 2019-10-25 设计创作，主要内容包括：本发明涉及新型钌基自支撑电催化材料及其制备方法和在电催化氮气还原产氨中的应用。将氧化石墨烯与RuCl<Sub>3</Sub>溶液超声混合,再加入适量还原剂和联结剂,所得混合液放入聚四氟乙烯内衬的反应釜中,120℃下高温反应14h,冷却,所得产物用乙醇和水混合液洗涤,自然干燥,得新型钌基自支撑电催化材料Ru@GA。本发明得到了一种结构稳定、导电性能良好和具有自支撑性的高效氮气还原产氨电催化材料。制备方法简单、无需冷冻干燥、重复性好,所得Ru纳米粒子粒径均在2-4nm左右,有利于催化性能的提高,在电催化氮气还原产氨等领域有广阔的应用前景。(The invention relates to a novel ruthenium-based self-supporting electro-catalytic material, a preparation method thereof and application thereof in electro-catalytic nitrogen reduction for producing ammonia. Reacting graphene oxide with RuCl 3 Ultrasonically mixing the solution, adding a proper amount of reducing agent and coupling agent, putting the obtained mixed solution into a reaction kettle with a polytetrafluoroethylene lining, reacting for 14 hours at a high temperature of 120 ℃, cooling, washing the obtained product with the mixed solution of ethanol and water, and naturally drying to obtain the novel ruthenium-based self-supporting electrocatalytic material Ru @ GA. The invention obtains the high-efficiency ammonia-reduction electro-catalytic material with stable structure, good conductivity and self-supporting property. The preparation method is simple, freeze drying is not needed, the repeatability is good, the grain diameter of the obtained Ru nano particles is about 2-4nm, the improvement of the catalytic performance is facilitated, and ammonia is produced in the electro-catalysis nitrogen reduction processAnd the like, and has wide application prospect.)

1. The novel ruthenium-based self-supporting electrocatalytic material is characterized in that the novel ruthenium-based self-supporting electrocatalytic material is obtained by loading Ru nano particles on a carbon material substrate by a hydrothermal method.

2. The novel ruthenium-based self-supporting electrocatalytic material as claimed in claim 1, wherein the carbon material substrate is reduced graphene oxide aerogel GA.

3. A preparation method of a novel ruthenium-based self-supporting electrocatalytic material is characterized by comprising the following steps: reacting graphene oxide with RuCl₃Ultrasonically mixing the solution, adding a proper amount of reducing agent and coupling agent, putting the obtained mixed solution into a reaction kettle with a polytetrafluoroethylene lining, reacting for 14 hours at a high temperature of 120 ℃, cooling, washing the obtained product with the mixed solution of ethanol and water, and naturally drying to obtain the novel ruthenium-based self-supporting electrocatalytic material Ru @ GA.

4. The method according to claim 3, wherein the reducing agent is ethylenediamine.

5. The method of claim 3, wherein the coupling agent is sodium borate.

6. The preparation method according to claim 3, wherein the preparation method of the graphene oxide is as follows: adding high-purity graphite powder and sodium nitrate into concentrated sulfuric acid in sequence at 0 ℃, uniformly stirring, then adding a small amount of potassium permanganate in batches, keeping the temperature below 20 ℃, completing addition for about 1h, reacting for about 40min at 35 ℃ after the color of the mixture changes from purple to grass green, stopping heating, standing at normal temperature for 72h, slowly injecting the obtained product into hot water at 70 ℃, dropwise adding 30% of hydrogen peroxide and stirring until the mixed solution becomes bright yellow, centrifuging while hot, washing with distilled water at 60 ℃, neutralizing redundant acid with 5 wt% of sodium carbonate solution to neutrality, centrifuging, washing until the supernatant is free of sulfate ions, and drying at 60 ℃ to obtain graphene oxide.

7. Use of the novel ruthenium-based self-supporting electrocatalytic material as claimed in claim 1 for electrocatalytic nitrogen reduction to ammonia.

Technical Field

The invention belongs to the field of catalyst materials, and particularly relates to preparation of a novel ruthenium-based self-supporting electrocatalytic material with high catalytic performance on ammonia production by nitrogen reduction and application of the material in an electrocatalytic ammonia production reaction by nitrogen reduction.

Background

Ammonia (NH)₃) Is one of the most important chemical raw materials in the society at present. Easy to liquefy, store and transport, is an ideal hydrogen carrier, and is an important energy substance for sustainable development of human society. Currently, the global demand for ammonia is increasing. The industrial production of ammonia is mainly the traditional Haber-Bosch process, which requires high temperature (450 ℃.), high pressure (150 ℃.) (350 atm), harsh conditions, large pollution and large energy consumption (the energy consumed in the production process of the method accounts for about 1 percent of the annual energy consumption in the world). In recent years, the synthesis of ammonia by Electrocatalytic Nitrogen Reduction Reaction (ENRR) is one of the most promising green and sustainable ammonia production methods, which is a process of reducing nitrogen into ammonia gas by using nitrogen and water as raw materials under normal temperature and pressure and driven by electric energy. Therefore, the development of an efficient electro-catalytic ammonia-producing catalyst for nitrogen reduction is the key for accelerating the realization of industrialization of electro-catalytic ammonia production by nitrogen reduction. Researches show that the ruthenium-based catalyst has higher catalytic activity for electro-catalysis of the ammonia production reaction by nitrogen reduction, but ruthenium metal is rare and poor in utilization rate, so that the use of the material is greatly limited. The graphene aerogel is a three-dimensional self-supporting material with a porous structure, has good electrical conductivity, a large specific surface area and good mass transfer performance, and can effectively improve the catalytic performance of metal. Thus immobilizing ruthenium nanoparticles to grapheneThe development of a ruthenium-based electro-catalyst material with simple preparation method, good repeatability and high catalytic efficiency on the surface of the aerogel can greatly promote the development of an electro-catalytic ammonia production technology.

Disclosure of Invention

The invention aims to provide a preparation method of a novel ruthenium-based self-supporting electro-catalytic material, which has the advantages of simple preparation method, good repeatability and high catalytic efficiency.

The technical scheme adopted by the invention is as follows: the novel ruthenium-based self-supporting electrocatalytic material is obtained by loading Ru nano particles on a carbon material substrate by a hydrothermal method.

Further, in the novel ruthenium-based self-supporting electrocatalytic material, the carbon material substrate is reduced graphene oxide aerogel GA.

A preparation method of a novel ruthenium-based self-supporting electrocatalytic material comprises the following steps: reacting graphene oxide with RuCl₃Ultrasonically mixing the solution, adding a proper amount of reducing agent and coupling agent, putting the obtained mixed solution into a reaction kettle with a polytetrafluoroethylene lining, reacting for 14 hours at a high temperature of 120 ℃, cooling, washing the obtained product with the mixed solution of ethanol and water, and naturally drying to obtain the novel ruthenium-based self-supporting electrocatalytic material Ru @ GA.

Further, in the above preparation method, the reducing agent is ethylenediamine.

Further, in the above preparation method, the coupling agent is sodium borate.

Further, in the preparation method, the preparation method of the graphene oxide comprises the following steps: adding high-purity graphite powder and sodium nitrate into concentrated sulfuric acid in sequence at 0 ℃, uniformly stirring, then adding a small amount of potassium permanganate in batches, keeping the temperature below 20 ℃, completing addition for about 1h, reacting for about 40min at 35 ℃ after the color of the mixture changes from purple to grass green, stopping heating, standing at normal temperature for 72h, slowly injecting the obtained product into hot water at 70 ℃, dropwise adding 30% of hydrogen peroxide and stirring until the mixed solution becomes bright yellow, centrifuging while hot, washing with distilled water at 60 ℃, neutralizing redundant acid with 5 wt% of sodium carbonate solution to neutrality, centrifuging, washing until the supernatant is free of sulfate ions, and drying at 60 ℃ to obtain graphene oxide.

The invention also provides application of the novel ruthenium-based self-supporting electro-catalytic material in electro-catalytic nitrogen reduction for producing ammonia.

The invention has the beneficial effects that: the invention provides a simple and feasible method for preparing a high-efficiency ruthenium-based catalyst, the method has universality in preparation of ruthenium-based catalyst materials taking carbon materials such as graphene aerogel and the like as substrates, the catalyst Ru @ GA prepared by the method can be efficiently recycled in a catalytic system, the catalyst has uniform particle size and smaller size, a binder is not needed in use, and the catalytic efficiency of the catalyst is further improved. The catalyst material prepared by the method has good application prospect in the aspect of electro-catalysis of nitrogen reduction to produce ammonia.

Drawings

FIG. 1 is an SEM image of Ru @ GA prepared in example 1.

FIG. 2 is a TEM image of Ru @ GA prepared in example 1.

FIG. 3 is an XPS plot of Ru @ GA prepared in example 1.

FIG. 4 is a diagram of the apparatus used to electrocatalyze the nitrogen reduction to ammonia reaction with the self-supporting electrocatalyst Ru @ GA of example 2.

Detailed Description