Supported Medium-Entropy Alloy Catalysts for Ammonia Decomposition

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Solution Overview

Problem

Existing catalysts for ammonia decomposition are prone to deactivation by nitrogen species and catalyst particle agglomeration, limiting their effectiveness and economic viability for large-scale hydrogen production.

Innovation Solution

The use of supported medium entropy metal alloy (MEA) catalysts, composed of three or four principal metals, which include Co, Cr, Fe, Mn, Ni, Al, Cu, Zn, Ti, Zr, Mo, V, Ru, Rh, Pd, Ag, W, Re, Ir, Pt, Au, Ce, Y, Yb, Sn, Ga, and Be, supported on metal oxides, carbon materials, or metal organic frameworks, to catalytically decompose ammonia into hydrogen and nitrogen at lower temperatures, suppressing particle agglomeration and enhancing catalytic performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional catalysts are used for ammonia decomposition, then catalytic activity is achieved, but catalyst deactivation occurs due to nitrogen species accumulation and particle agglomeration

Engineering Contradiction:

Improvecatalyst stabilityVSAvoidcatalyst activity

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The invention changes the compositional parameters of the catalyst by using medium entropy alloys with specific atomic ratios (e.g., M1:M2:M3 = 1:1:1 or M1:M2:M3:M4 = 1:1:1:1) and controlled particle sizes (1-100 nm), which fundamentally alters the catalyst's resistance to deactivation while maintaining high activity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention employs composite material structures where medium entropy alloys are supported on high-surface-area substrates (alumina, silica, titania, carbon materials), creating a composite system that prevents particle agglomeration and enhances stability while maintaining catalytic activity

Inventive Principle:

Principle #40Composite materials

2Productivity

If reaction temperature is increased to improve ammonia decomposition rate, then productivity increases, but energy consumption increases

Engineering Contradiction:

Improveammonia decomposition rateVSAvoidenergy consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The invention changes the catalytic parameters by using medium entropy alloys with specific compositions and nanostructures that lower the activation energy barrier, enabling high decomposition rates at reduced temperatures (400-600°C) compared to conventional catalysts

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention replaces thermal energy input with catalytic activity enhancement, where the medium entropy alloy catalyst provides alternative reaction pathways with lower activation energy, substituting the need for high thermal input

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If catalyst particle size is reduced to improve activity, then catalytic performance improves, but particle agglomeration increases

Engineering Contradiction:

Improvecatalytic activityVSAvoidparticle dispersion

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The invention introduces a support material as an intermediary between catalyst particles, which physically separates and stabilizes nano-sized particles (1-100 nm), preventing their agglomeration while maintaining their high surface area and catalytic activity

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention uses porous support materials with high surface area (alumina, silica, titania, activated carbon) that provide numerous anchoring sites for catalyst particles, preventing agglomeration through physical confinement and surface interaction

Inventive Principle:

Principle #31Porous materials

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 MEA catalysts achieve high conversion and hydrogen yield with improved activity and stability at lower reaction temperatures (400° C.-600° C.), reducing energy consumption and costs, and are more economically viable for industrial applications.

Implementation Method 1

catalytically decomposing the ammonia into hydrogen and nitrogen over the supported MEA catalyst in the reactor at a reaction temperature between 200° C. and 900° C.

Methodology Applied

Scientific EffectCatalysis: Catalysis

Data Source

PatentUS20250332578A1Ammonia decomposition over supported medium entropy metal alloy catalysts

Publication Date: 2025.10.30 SAUDI ARABIAN OIL CO

AI summary

A method of catalytic ammonia decomposition, where the method includes: flowing ammonia into a reactor charged with a supported medium entropy metal alloy (MEA) catalyst including MEA particles supported on a support, the MEA particles including a first principal metal, a second principal metal, and a third principal metal, where each of the principal metals is independently selected without repetition from the group consisting of Co, Cr, Fe, Mn, Ni, Al, Cu, Zn, Ti, Zr, Mo, V, Ru, Rh, Pd, Ag, W, Re, Ir, Pt, Au, Ce, Y, Yb, Sn, Ga, In, and Be; and catalytically decomposing the ammonia into hydrogen and nitrogen over the supported MEA catalyst in the reactor at a reaction temperature between 200° C. and 900° C.