CN-116529427-B - Composite comprising platinum-alkaline earth metal alloy, fuel cell comprising the same, and water electrolysis cell and method for producing the same

Abstract

The present invention relates to a composite having advantages of economy, excellent catalyst activity, and significantly improved stability over conventional pure platinum catalysts, and more specifically, to a composite according to the present invention, which comprises a carbon support and a binary alloy supported on the carbon support and containing platinum (Pt) and an alkaline earth metal, wherein, in Pt 4f XPS spectrum of the binary alloy based on X-ray photoelectron spectroscopy (XPS), E1 and E2 defined by the following formulas 1 and 2 satisfy the following formula 3. (formula 1) e1=e0-E0 (ref) (formula 2) e2=eii-EII (ref) (formula 3) E1/E2 is less than or equal to 0.85, wherein in formula 1 and formula 2, E0 (ref) and EII (ref) are respectively the binding energy (center) of the Pt (0) peak and the binding energy (center) of the Pt (II) peak in the Pt 4f XPS spectrum of pure platinum (Pt), and E0 and EII are respectively the binding energy (center) of the Pt (0) peak and the binding energy (center) of the Pt (II) peak in the Pt 4f XPS spectrum of the binary alloy.

Inventors

• YU ZONGCHENG
• Barima Kaleb Gian

Assignees

• 大邱庆北科学技术院

Dates

Publication Date

20260512

Application Date

20221101

Priority Date

20211101

Claims (6)

1. 1. A method of preparing a complex comprising the steps of: a) Preparing a mixture comprising a platinum precursor, an alkaline earth metal precursor, a first reducing agent, and an aprotic organic solvent; b) Naturally cooling the mixture after a first heat treatment under conditions above the boiling point of the organic solvent, thereby preparing a colloid comprising a composition; c) Centrifuging the colloid to obtain a composition; d) Mixing the composition with a powdery second reducing agent, applying to a carbon support, performing a second heat treatment under an inert reducing atmosphere to induce alloying between platinum and alkaline earth metal, and E) Removing impurities contained in the alloyed composition by acid treatment, Wherein the aprotic organic solvent is selected from acetonitrile, dimethylacetamide, dimethylformamide, dimethyl sulfoxide, methyl ethyl ketone, methyl N-propyl ketone, N More than one of methyl pyrrolidone, propylene carbonate, nitromethane, sulfolane and hexamethylphosphoric triamide, The composition of step b) comprises crystalline platinum and an amorphous alkaline earth metal.
2. 2. The method for producing a complex according to claim 1, wherein, The steps a), b) and d) are performed under anhydrous and anaerobic conditions.
3. 3. The method for producing a complex according to claim 1, wherein, The first heat treatment of step b) is performed for 11 hours to 30 hours.
4. 4. The method for producing a complex according to claim 1, wherein, The second heat treatment is performed at a temperature of 300 ℃ to 1000 ℃.
5. 5. The method for producing a complex according to claim 1, wherein, The alkaline earth metal precursor is a chloride comprising more than one selected from calcium, magnesium, strontium, barium, radium and beryllium.
6. 6. The method for producing a complex according to claim 1, wherein, Forming a platinum coating on the surface of the alloyed composition by means of the acid treatment of step e).

Description

Composite comprising platinum-alkaline earth metal alloy, fuel cell comprising the same, and water electrolysis cell and method for producing the same Technical Field The present invention relates to a composite body including a platinum-alkaline earth metal alloy, a fuel cell and a water electrolysis cell including the same, and a method of manufacturing the same, and more particularly, to a composite body including a platinum-based alloy excellent in catalyst activity for an oxygen reduction reaction or a hydrogen evolution reaction and significantly improved in durability, a fuel cell and a water electrolysis cell including the same, and a method of manufacturing the same. Background As a fuel cell and a water electrolysis cell for environmental protection energy conversion production, a catalyst is necessary for improving energy conversion efficiency. As an example, in the case of proton exchange membrane fuel cells, platinum (Pt) is mainly used as a catalyst to promote oxygen reduction reaction in the cathode (ORR: oxygen reduction reaction) and hydrogen oxidation reaction in the anode (HOR: hydrogen oxidation reaction). In particular, the oxygen reduction reaction in the cathode is slower than the hydrogen oxidation reaction in the anode, so that the reaction rate thereof determines the formation of the whole fuel cell, and thus a pure platinum catalyst is currently mainly used to promote the oxygen reduction reaction in the cathode. However, the high price and scarcity of platinum as a noble metal limit large-scale applications. To overcome these problems, research into platinum-based catalysts that alloy platinum with a second metal such as cobalt, nickel, iron, manganese or copper is actively underway. In korean laid-open patent No. 10-2020-0023080, although an alloy nanoparticle catalyst alloyed with platinum and an excessive metal is provided, improvement in activity, durability and economical efficiency is still required in practice. Therefore, in order to improve the efficiency of the fuel cell, it is necessary to provide a catalyst having improved activity and durability while having economical efficiency. Although alkaline earth metals are very abundant in nature and have a relatively low cost as compared with other metals, since the high negative electrode reduction potential (negative reduction potential) of alkaline earth metals, the reduction potential difference of platinum and alkaline earth metals is large, and thus synthesis for alloying with platinum is difficult, and particularly synthesis of platinum-alkaline earth metal alloys is difficult, particulate alloys have been hardly reported in the literature. In contrast, if a new synthesis method capable of overcoming such a reduction power source difference to prepare a granular alloy is developed, the alloy requires a very large energy when dealloying, and thus can be a new platinum substrate alloy material capable of having both stability and activity. Therefore, development of a platinum alloy catalyst which has not only the activity and durability of the catalyst but also economy and is therefore practically applicable to fuel cells has been desired. [ PRIOR ART ] [ Patent literature ] Korean laid-open patent No. 10-2020-0023080 Disclosure of Invention Technical problem The purpose of the present invention is to provide a composite body that has excellent catalyst activity and stability and is economical. Another object of the present invention is to provide a catalyst for oxygen reduction reaction and a water electrolysis cell, a cathode for a fuel cell and a water electrolysis cell, comprising the composite of the present invention. It is a further object of the present invention to provide a fuel cell and a water electrolysis cell comprising the cathode for a fuel cell and a water electrolysis cell of the present invention. It is a further object of the present invention to provide a method for preparing a complex according to the present invention. Technical proposal The composite according to one aspect of the present invention includes a carbon support, and a binary alloy supported on the carbon support and containing platinum (Pt) and an alkaline earth metal, wherein, in Pt 4f XPS spectrum of the binary alloy based on X-ray photoelectron spectroscopy (XPS), E1 and E2 specified by the following formulas 1 and 2 satisfy the following formula 3. (1) E1=E0-E0(ref) (2) E2=EII-EII (ref) (3) E1/E2≤0.85 In the formulas 1 and 2, E0 (ref) and EII (ref) are the binding energy (center) of the Pt (0) peak and the binding energy (center) of the Pt (II) peak in the Pt 4f XPS spectrum of pure platinum (Pt), respectively, and E0 and EII are the binding energy (center) of the Pt (0) peak and the binding energy (center) of the Pt (II) peak in the Pt 4f XPS spectrum of the binary alloy, respectively. In the composite according to an embodiment of the present invention, the alkaline earth metal may Be one or more selected from the group consist