Transition Metal-Supported Intermetallic Catalyst for Ammonia Synthesis

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Electrides are chemically unstable, particularly under ordinary temperature conditions, and have limitations in handling and reaction conditions, with conventional production methods being complex and equipment-intensive, and intermetallic compounds like Y5Si3 are unsuitable for catalytic chemistry due to small specific surface areas.

Innovation Solution

A transition metal-supported intermetallic compound with a specific composition, where a rare earth element is combined with Si or Ge, and a transition metal from group 8, 9, or 10 is supported, offering improved chemical stability and electron-donating ability, suitable for ammonia synthesis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If conventional electrides are used as catalysts, then high reaction activity is achieved, but chemical stability deteriorates significantly

Engineering Contradiction:
Improvereaction activityVSAvoidchemical stability
Core Design Contradiction:
PowerVSStability of the object's composition

Solution Approach 1:

The patent uses a composite structure consisting of an intermetallic compound core (A5X3) with embedded electrons and a transition metal shell. This composite design combines the high reaction activity of electride materials with the chemical stability of intermetallic compounds, resolving the contradiction between catalytic activity and chemical stability.

Inventive Principle:
Principle #40Composite materials

2Quantity of substance

If conventional electride production methods are used, then electride is obtained, but manufacturing complexity increases and equipment requirements become intensive

Engineering Contradiction:
Improveelectride productionVSAvoidproduction method complexity
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent changes the production parameters by using arc melting or solid-phase reaction methods at relatively low temperatures (below 1000°C) to synthesize the intermetallic compound A5X3 with embedded electrons. This approach simplifies the manufacturing process and reduces equipment requirements compared to conventional electride production methods.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If intermetallic compounds like Y5Si3 are used, then chemical stability is improved, but specific surface area decreases making them unsuitable for catalytic chemistry

Engineering Contradiction:
Improvechemical stabilityVSAvoidspecific surface area
Core Design Contradiction:
Stability of the object's compositionVSArea of stationary object

Solution Approach 1:

The patent applies local quality by creating a core-shell structure where the intermetallic compound A5X3 forms the stable core, while the transition metal forms the catalytically active outer layer. This allows the interior to provide chemical stability while the surface provides high catalytic activity, effectively resolving the surface area limitation.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The intermetallic compound is more easily synthesized, stable in water, and effective as a catalyst for ammonia production, maintaining activity even in the presence of water, with enhanced reaction efficiency and reduced hydrogen poisoning.

Implementation Method 1

the intermetallic compound having a specific composition surprisingly has the properties of an electride, and has a high electron-donating ability, and is stable in water

Methodology Applied
Scientific EffectHydrogen absorption: Absorption (physical)

Implementation Method 2

a transition metal is supported on an intermetallic compound... the transition metal-supported intermetallic compound of the present invention can be used as a catalyst, as with the electride

Methodology Applied
Scientific EffectCatalysis: Catalysis

Data Source

PatentEP3395441B1Transition-metal-supported intermetallic compound, supported metallic catalyst, and ammonia producing method
Publication Date: 2023.03.08 TOKYO INST OF TECH
  • EP3395441B1 patent drawingFigure 1
  • EP3395441B1 patent drawingFigure 2
  • EP3395441B1 patent drawingFigure 3

AI summary

An electride, which is more stable and can be more easily obtained, is provided or is made available, and as a result, a catalyst particularly useful for chemical synthesis, in which the electride is particularly used, is provided. A transition metal-supported intermetallic compound having a transition metal supported on an intermetallic compound represented by the following formula (1):         A5X3 ...     (1) wherein A represents a rare earth element, and X represents Si or Ge.