阅读说明：本技术 一种基于酸性深共融溶剂的MXene负载金属单原子电催化剂制备方法 (Preparation method of MXene loaded metal monatomic electrocatalyst based on acidic deep eutectic solvent ) 是由 李长平 王玉伟 李琢 于 2020-04-03 设计创作，主要内容包括：本发明涉及一种基于酸性深共融溶剂的MXene负载金属单原子电催化剂制备方法,属于电催化剂制备技术领域。一种基于酸性深共融溶剂的MXene负载金属单原子电催化剂制备方法,所述MXene负载金属单原子电催化剂在少层MXene表面锚定以单个原子状态分散的电催化活性金属原子,按下述方法制得：将氢键受体、氢键供体与活性金属前驱体反应形成酸性三元深共融溶剂；将少层MXene在所得酸性三元深共融溶剂中处理得到MXene负载金属单原子电催化剂。本发明所述方法制备工艺简单,有利于规模化制备；酸性三元深共融溶剂可循环使用,有助于降低生产成本；少层MXene经酸性三元深共融溶剂处理,可高担载量负载活性金属单原子。(The invention relates to a preparation method of an MXene loaded metal monatomic electrocatalyst based on an acidic deep eutectic solvent, belonging to the technical field of electrocatalyst preparation. A method for preparing an MXene loaded metal monatomic electrocatalyst based on an acidic deep eutectic solvent is disclosed, wherein the MXene loaded metal monatomic electrocatalyst is prepared by anchoring electrocatalytic active metal atoms dispersed in a single atomic state on the surface of a few layers of MXene according to the following steps: reacting a hydrogen bond acceptor, a hydrogen bond donor and an active metal precursor to form an acidic ternary deep eutectic solvent; and treating a small layer of MXene in the obtained acidic ternary deep eutectic solvent to obtain the MXene-loaded metal monoatomic electrocatalyst. The method has simple preparation process and is beneficial to large-scale preparation; the acidic ternary deep eutectic solvent can be recycled, and is beneficial to reducing the production cost; the small-layer MXene is treated by an acidic ternary deep eutectic solvent, so that the active metal monoatomic can be loaded at high load.)

1. A preparation method of an MXene loaded metal monatomic electrocatalyst based on an acidic deep eutectic solvent is characterized by comprising the following steps:

mixing a hydrogen bond acceptor and a hydrogen bond donor according to a molar ratio of 1: 1-1: 4, and stirring at a constant temperature of 20-60 ℃ and at a speed of 100-800 rpm until a uniform and clear liquid is formed; adding an active metal precursor into the liquid, wherein the molar ratio of the active metal precursor to a hydrogen bond acceptor is 1: 0.1-1: 2, and keeping the temperature and the stirring speed unchanged until an acidic ternary deep co-melting solvent is formed;

adding a small layer of MXene into the obtained acidic ternary deep eutectic solvent, wherein the molar ratio of the small layer of MXene to a hydrogen bond acceptor is 1: 0.1-1: 2; stirring and reacting for 0.5-5 h at a constant temperature of 20-60 ℃ and at a speed of 100-800 rpm, centrifuging, washing with ethanol, and drying to obtain the MXene-loaded metal monoatomic electrocatalyst,

the metal precursor is SnCl₄、CoCl₃、NiCl₂、FeCl₃One kind of (1).

2. The method of claim 1, wherein: the hydrogen bond acceptor is choline chloride, and the hydrogen bond donor is one of hexafluorophosphoric acid, p-toluenesulfonic acid, citric acid and malonic acid.

3. The method of claim 1, wherein: the small layer MXene refers to a sheet material with the MXene layer number below 10.

4. The method of claim 1, wherein: the MXene is Ti₃C₂、Ta₄C₃、Nb₄C₃、Cr₂C、Ti₂C.

5. An MXene supported metal monatomic electrocatalyst produced by the method according to any one of claims 1 to 4.

6. The catalyst of claim 5, wherein: the MXene supported metal monoatomic electrocatalyst is formed by anchoring electrocatalytic active metal atoms dispersed in a single atomic state on the surface of a few layers of MXene.

Technical Field

The invention relates to a preparation method of an MXene supported metal monatomic catalyst based on an acidic deep eutectic solvent, belonging to the technical field of novel catalyst preparation.

Background

The catalyst is an indispensable raw material in chemical industry and has important significance for the development of human society. In recent years, researches show that the energy level and the electronic structure of unsaturated coordination atoms on the surface of the metal catalyst can be obviously changed, and the metal catalyst is a high-activity catalytic active site. The catalytic activity of the catalyst can be greatly improved by dispersing the catalytic active substance on the carrier in the form of single atom and enabling the catalyst to have an unsaturated coordination environment. An electrocatalyst for an electrochemical reaction system needs to use a high-conductivity material as a carrier and load active metal single atoms by means of chemical bonding and the like.

MXene is a novel two-dimensional transition metal carbide or nitride, has metalloid characteristics and high conductivity, contains a large number of electronegative functional groups such as hydroxyl on the surface, gives good affinity to a reaction medium, and is suitable for constructing a metal monoatomic electrocatalyst serving as a conductive substrate. The existing method for preparing the MXene loaded metal monoatomic electrocatalyst mainly comprises an electrochemical deposition method and a metal ion solution adsorption method. Wherein the electrochemical deposition method is complex in operation and is not beneficial to large-scale production [1 ]; the metal ion solution adsorption method needs to strictly control the ion concentration, when the concentration is too high, metal is easy to aggregate on the MXene surface to form particles, and when the concentration is too low, the monoatomic load is influenced [2 ]. The development of a novel MXene supported metal monoatomic electrocatalyst preparation technology is helpful for promoting the practicability of the metal monoatomic electrocatalyst.

Reference to the literature

[1]Zhang J,Zhao Y,Guo X,et al.Single platinum atoms immobilized on anMXene as an efficient catalyst for the hydrogen evolution reaction[J].NatureCatalysis,2018,1(12):985-992.

[2]Zhao D,Chen Z,Yang W,et al.MXene(Ti₃C₂)vacancy-confined single-atomcatalyst for efficient functionalization of CO₂[J].Journal of the AmericanChemical Society,2019,141(9):4086-4093.

Disclosure of Invention

The invention aims to provide a preparation method of an MXene supported metal monatomic electrocatalyst based on an acidic deep eutectic solvent. The invention forms an acidic deep co-melting solvent by selecting a proper hydrogen bond donor, and a ternary system is formed after metal ions are added into the acidic deep co-melting solvent; treating a small layer of MXene in an acidic deep eutectic solvent to form a surface defect position anchoring metal atom to form a monatomic electrocatalyst.

An MXene supported metal monatomic electrocatalyst based on an acidic deep eutectic solvent is prepared by mixing a hydrogen bond acceptor and a hydrogen bond donor according to a molar ratio of 1: 1-1: 4, and stirring at a constant temperature of 20-60 ℃ at a speed of 100-800 rpm until a uniform and clear liquid is formed; adding an active metal precursor into the liquid, wherein the molar ratio of the active metal precursor to a hydrogen bond acceptor is 1: 0.1-1: 2, and keeping the temperature and the stirring speed unchanged until an acidic ternary deep co-melting solvent is formed;

adding a small layer of MXene into the obtained acidic ternary deep eutectic solvent, wherein the molar ratio of the small layer of MXene to a hydrogen bond acceptor is 1: 0.1-1: 2; stirring and reacting for 0.5-5 h at a constant temperature of 20-60 ℃ and at a speed of 100-800 rpm, centrifuging, washing with ethanol, and drying to obtain the MXene-loaded metal monoatomic electrocatalyst,

the metal precursor is SnCl₄、CoCl₃、NiCl₂、FeCl₃One kind of (1).

In the technical scheme, the hydrogen bond acceptor is choline chloride, and the hydrogen bond donor is one of hexafluorophosphoric acid, p-toluenesulfonic acid, citric acid and malonic acid.

In the above technical scheme, the metal precursor is SnCl₄、CoCl₃、NiCl₂、FeCl₃One kind of (1).

In the technical scheme, the small-layer MXene refers to a sheet material with the MXene layer number being less than 10.

Further, MXene is Ti₃C₂、Ta₄C₃、Nb₄C₃、Cr₂C、Ti₂C.

Another object of the present invention is to provide an MXene-supported metal monatomic electrocatalyst obtained by the above method, which anchors electrocatalytically active metal atoms dispersed in a single atomic state on the surface of a few layers of MXene.

The invention has the beneficial effects that: the used acidic ternary deep eutectic solvent has good chemical stability, strong designability and nonflammability, and is beneficial to the large-scale preparation of the MXene loaded metal monoatomic electrocatalyst; the acidic ternary deep eutectic solvent can be recycled, and is beneficial to reducing the preparation cost; a small amount of MXene is treated by an acidic ternary deep eutectic solvent, and a large number of defect sites are formed on the surface of the MXene and can be used for anchoring active metal single atoms and improving the loading capacity.

Drawings

Fig. 1 is a scanning transmission electron microscope high angle annular dark field photograph of MXene supported Sn monatomic electrocatalyst according to example 1 of the present invention.

Fig. 2 is an X-ray diffraction pattern of MXene supported Sn monatomic electrocatalyst according to example 1 of the present invention.

Fig. 3 is a synchrotron radiation X-ray absorption spectrum of MXene supported Sn monatomic electrocatalyst prepared in example 1 of the present invention.

Detailed Description

The following non-limiting examples are presented to enable those of ordinary skill in the art to more fully understand the present invention and are not intended to limit the invention in any way.

The test methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials are commercially available, unless otherwise specified.