Platinum-Alumina Catalyst Eggshell Design for Dehydrogenation
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Solution Overview
Problem
Conventional platinum-loaded alumina catalysts suffer from high diffusion resistance, leading to insufficient reaction and catalyst deterioration due to sintering or coking, limiting their industrial application and catalyst life, particularly in dehydrogenation reactions for hydrogen energy carriers.
Innovation Solution
A platinum-loaded alumina catalyst with controlled platinum particle diameters and distribution, utilizing a γ-alumina carrier with specific surface area, pore volume, and pore diameter, and optionally containing sulfur and alkali metals, to enhance catalyst life and dispersion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If platinum compound is adsorbed by the outer shell part of the alumina carrier, then the catalyst structure is simplified, but the diffusion resistance increases and reaction efficiency decreases
Solution Approach 1:
The patent applies local quality by creating an eggshell-type catalyst where platinum is selectively distributed in the outer shell region (0-0.5mm from surface) rather than uniformly throughout. This localized platinum distribution in the outer 0.5mm layer reduces diffusion path lengths for reactants and products, improving reaction efficiency while maintaining structural simplicity.
2Productivity
If active metal is loaded only on the outer shell of the catalyst particles, then the diffusion resistance is reduced, but the active metal particles cannot be sufficiently dispersed
Solution Approach 1:
The patent controls the platinum particle size parameter within a specific range (0.5-5μm average diameter) through optimized impregnation and calcination conditions. This parameter control ensures sufficient dispersion of platinum particles in the outer shell region while maintaining the eggshell structure, resolving the contradiction between diffusion rate and metal dispersion.
3Productivity
If a large amount of active metal is loaded on the outer shell, then the catalytic activity increases, but catalyst deterioration due to sintering or coking occurs
Solution Approach 1:
The patent optimizes the platinum loading amount parameter to 0.1-5.0 wt% (preferably 0.3-3.0 wt%) and controls particle size at 0.5-5μm. This parameter optimization balances catalytic activity with resistance to sintering and coking, improving catalyst stability while maintaining high activity.
Solution Approach 2:
The patent uses γ-alumina as a support material with specific properties (surface area 150-300m²/g, pore volume 0.3-0.6ml/g) to create a composite catalyst structure. The γ-alumina support provides high surface area for platinum dispersion and enhances catalyst stability, preventing sintering and coking while maintaining catalytic activity.
4Productivity
If the pore size of the catalyst is increased to reduce diffusion resistance, then the reaction efficiency improves, but the surface area of the carrier decreases
Solution Approach 1:
The patent applies local quality by concentrating platinum in the outer shell region (0-0.5mm) where reactant concentration is highest. This allows the use of moderate pore sizes (0.3-0.6ml/g) throughout the carrier while achieving high reaction efficiency through localized catalytic activity, avoiding the need to increase overall pore size which would reduce surface area.
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 catalyst exhibits improved catalyst life from 1-2 years to 3-4 years, reducing replacement frequency and costs, and is suitable for dehydrogenation reactions in hydrogen energy storage and transportation systems.
Implementation Method 1
a platinum-loaded alumina catalyst in which platinum is loaded on an alumina carrier, a method of producing the same, and a method of dehydrogenating a hydrogenated aromatic using the catalyst
Implementation Method 2
since the platinum atom with the atomic weight 195 has a large mass and the adsorbability of a platinum compound used as a platinum source to the catalyst carrier is high, the platinum compound is adsorbed by and fixed to the outer shell part of the alumina carrier
Data Source
Figure 1(A)~1(B)
Figure 2(A)~2(B)
Figure 3
AI summary
[Task] To provide a platinum-loaded alumina catalyst with an improved catalyst life. [Solution] A platinum-loaded alumina catalyst includes an alumina carrier, and platinum loaded on the alumina carrier, wherein the alumina carrier includes a γ-alumina carrier having a surface area of 200 m2/g or more, a pore volume of 0.50 m2/g or more, an average pore diameter in a range of 60 to 150 Å, with pores having a pore diameter in a range of ± 30 Å from the average pore diameter occupying 60 % or more of a total pore volume, platinum particles are loaded on γ-alumina carrier in a range of 0.1 to 1.5 % by weight calculated as elemental platinum (Pt), and 70 % or more of the platinum particles have a size of 8 to 15 Å by direct observation using a transmission electron microscope.