JP-2026075985-A - Gold-supported catalyst and method for producing the same, and method for producing anilines and hydrogen gas using the gold-supported catalyst

Abstract

[Problem] In methods for producing anilines by reducing aromatic nitro compounds, which are unreducible substances, H2 and petroleum-derived alcohols have been used as reducing agents, but there have been problems in terms of safety and environmental impact. [Solution] The present invention provides a method for reducing aromatic nitro compounds, which is characterized by high safety and low environmental impact because it uses polysaccharides such as cellulose or polyols and an aqueous solvent in the presence of a gold-supported catalyst obtained by immobilizing gold nanoparticles on the surface of an inorganic crystalline support. [Selection Diagram] None

Inventors

• 能島 明史
• 本馬 洋子

Assignees

• 株式会社KRI

Dates

Publication Date

20260511

Application Date

20241023

Claims (4)

1. A catalyst used to reduce a reducible substance using a hydrogenation source material, The hydrogenation source substance is a polysaccharide or a polyol. A gold-supported catalyst characterized in that zero-valent gold particles with a diameter of 10 nm or less are supported on the surface of a crystalline solid.
2. A catalyst used to generate hydrogen gas by dehydrogenating a hydrogenation source substance in the liquid phase, The hydrogenation source substance is a polysaccharide or a polyol. A gold-supported catalyst characterized in that zero-valent gold particles with a diameter of 10 nm or less are supported on the surface of a crystalline solid.
3. A method for generating hydrogen gas by reacting a gold-supported catalyst according to claim 1 or 2 with a hydrogenation source material.
4. A method for producing anilines by reducing an aromatic nitro compound using a hydrogen source obtained by reacting a gold-supported catalyst according to claim 1 or 2 with a hydrogenated substance.

Description

Application for application of Article 30, Paragraph 2 of the Patent Law filed. KRI Client Conference & Workshop 2024, https://www.kri-inc.jp/conference-op/, October 17, 2024. This invention relates to a gold-supported catalyst used for reducing a reducible substance using polysaccharides or polyols as a hydrogenation source, a method for producing the catalyst, a method for producing anilines using the catalyst, and a gold-supported catalyst used for generating hydrogen gas by dehydrogenating polysaccharides or polyols in a solvent, a method for producing the catalyst, and a method for producing hydrogen gas using the catalyst. Chemical reactions utilizing molecular hydrogen ( H₂ ) are widely used in applications such as hydrogenation of organic matter, hydrogenation of oils and fats, hydrogen peroxide synthesis, oxygen scavenging, and reduction of metal species. However, H₂ is a flammable gas with a wide explosive range, and its small molecular size can lead to gas leaks and metal embrittlement, posing safety challenges. To address these issues, reactions using hydrogen sources other than H₂ are one possible solution. Reactions that extract hydrogen from compounds other than H2 and utilize it as a hydrogenation source are called hydrogen transfer reactions. Traditionally, these hydrogen transfer reactions have been carried out using primary or secondary alcohols as hydrogen sources, but there have been challenges such as the high environmental impact due to the petroleum-derived components and the need for safety measures because they are volatile organic substances. Non-patent documents 1 to 3 describe methods for reducing aromatic nitro compounds to anilines without using H2 , but these reports utilize alcohols and organic solvents, which are petroleum-derived components with high environmental impact. As volatile organic substances are used as reducing agents, safety measures remain a concern. S. Farhadi and F. Siadatnas, J. Mol. Catal. A: Chemical, 2011, 339, 108.M. B. Gawande, A. K. Rathi, P. S. Branco, I. D. Nogueira, A. Velhinho, J. J. Shrikhande, U. U. Indulkar, R. V. Jayaram, C. Ghumman, N. Bundaleski and O. Teodoro, Chem. Eur. J. 2012, 18, 12628H. Min, S. Lee, M. Park, J. Hwang, H. M. Jung and S. Lee, J. Organometallic Chem. 2014, 755, 7 This image shows the TEM observation results of the gold nanoparticle immobilized catalyst from Manufacturing Example 1.This image shows the TEM observation results of the gold nanoparticle immobilized catalyst from manufacturing example 6. [Gold-supported catalyst] One embodiment of the present invention is a gold-supported catalyst used for hydrogenating a reducible substance using polysaccharides or polyols as a hydrogenation source, wherein gold particles are supported on the surface of a crystalline solid. Furthermore, one embodiment of the present invention is a gold-supported catalyst used to generate hydrogen gas by dehydrogenating polysaccharides or polyols in an aqueous solvent, wherein gold particles are supported on the surface of a crystalline solid. In this invention, the gold-supported catalyst used is a gold nanoparticle-immobilized catalyst obtained by immobilizing gold nanoparticles on the surface of a support. (carrier) Examples of carriers for the gold-supported catalyst in the present invention include inorganic crystalline carriers and activated carbon. Examples of raw materials for inorganic crystalline carriers include metal oxides, layered clay minerals, and fibrous clay minerals. Among these, metal oxides or layered clay minerals are preferred from the viewpoint of significantly exhibiting the effects of the present invention. Examples of metal oxides include alumina ( Al₂O₃ ) and titania ( TiO₂ ). Examples of layered clay minerals include hydrotalcite. Furthermore, examples of supports for the gold-supported catalyst in the present invention include solid basic materials. Specifically, these include hydrotalcite, alumina ( Al₂O₃ ), titania ( TiO₂ ), and mixtures thereof. Hydrotalcite is preferred in the present invention because it yields the highest yield of anilines. Hereinafter, a gold nanoparticle-immobilized catalyst using hydrotalcite as a support, in which gold nanoparticles are immobilized on the surface of the hydrotalcite support, may be referred to as "Au/HT". The hydrotalcite used in this invention may be naturally occurring hydrotalcite, synthetic hydrotalcite, or a synthetic hydrotalcite-like compound; it is not particularly limited. In this invention, hydrotalcite may be a commercially available product from Fujifilm Wako Chemical Co., Ltd. or other manufacturers. Hydrotalcite is, for example, expressed by the following formula (1) M II 8-X M III X (OH) 16 A・nH 2 O (1) (In the formula, M II is at least one divalent metal selected from the group consisting of Mg²⁺ , Zn²⁺ , Ca²⁺ , Ni²⁺ , and Cu²⁺ , and M III is at least one trivalent metal selected from the group consisting of Al³⁺ , Ga³⁺ , Fe³⁺ , and Mn³⁺ . x represents a