Hollow Carbon Core-Shell Catalyst for Fuel Cell
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Solution Overview
Problem
Current polymer electrolyte fuel cells (PEFC) face challenges in reducing platinum usage costs and improving catalytic activity, particularly with conventional core-shell catalysts that do not effectively utilize hollow carbon carriers for supporting catalyst particles.
Innovation Solution
The development of an electrode catalyst with a core-shell structure where catalyst particles are supported both inside and outside the mesopores of a hollow carbon carrier, with a core portion of Pd and a shell portion of Pt, ensuring at least 50% of the catalyst particles are inside the mesopores, enhancing catalytic activity and reducing platinum dissolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional core-shell catalyst particles are used with solid carbon carriers, then the catalyst structure is simple to manufacture, but the catalytic activity is insufficient and platinum dissolution occurs
Solution Approach 1:
The patent employs hollow carbon carriers with specifically controlled pore sizes (2-50 nm) to support catalyst particles. The porous structure increases the surface area for catalyst support, allows better mass transport of reactants and products, and prevents platinum dissolution while maintaining high catalytic activity. The pore size distribution is optimized to balance gas transportability and catalyst support capacity.
Solution Approach 2:
The patent implements a nested structure where catalyst particles are positioned both inside the hollow carbon carrier and on its outer surface. This nested arrangement maximizes the utilization of the hollow carbon carrier's internal and external surfaces, increasing the effective catalyst support area while maintaining a relatively simple overall structure.
2Productivity
If hollow carbon carriers are used to support catalyst particles, then gas transportability is improved, but catalyst particles may not be effectively retained inside the pores
Solution Approach 1:
The patent optimizes the pore size parameters of the hollow carbon carrier (2-50 nm range) to achieve the right balance between gas transportability and catalyst particle retention. The pore size is controlled to be large enough for efficient gas diffusion but small enough to effectively retain catalyst particles within the carrier structure.
3Quantity of substance
If the amount of platinum is reduced to lower costs, then manufacturing cost decreases, but catalytic activity and durability are compromised
Solution Approach 1:
The patent uses a composite structure combining hollow carbon carriers with core-shell catalyst particles (Pd core with Pt shell). This composite material approach allows reduced platinum content while maintaining high catalytic activity through the synergistic effect of the hollow carbon support and the core-shell structure, which protects platinum from dissolution and maximizes its utilization.
4Area of stationary object
If catalyst particles are supported only on the outer surface of carriers, then the manufacturing process is simple, but the effective reaction surface area is limited
Solution Approach 1:
The patent transitions from two-dimensional surface support to three-dimensional utilization by positioning catalyst particles both inside the hollow carbon carrier and on its outer surface. This spatial arrangement in multiple dimensions significantly increases the effective reaction surface area while maintaining a straightforward manufacturing approach where catalyst ink is applied to the carrier.
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
This configuration achieves improved catalytic activity and cost reduction by minimizing platinum poisoning and dissolution, leading to enhanced performance and durability of the fuel cell.
Implementation Method 1
a hollow carbon carrier having a mesopore of a pore size of 2 to 50 nm, and a catalyst particle supported on the carrier
Implementation Method 2
the catalyst particle has a core portion formed on the carrier, and a shell portion formed so as to cover at least a part of the surface of the core portion
Data Source
AI summary
Provide an electrode catalyst with excellent catalytic activity that can contribute to cost reduction of PEFC. The electrode catalyst includes a hollow carbon carrier with mesopores with a pore size of 2 to 50 nm and a catalyst particle supported on the carrier. The catalyst particle is supported on both inside and outside the mesopores of the carrier, and have a core portion formed on the carrier and a shell portion covering at least a part of the surface of the core portion. Pd is included in the core portion, and Pt is included in the shell portion, and when the analysis of the particle size distribution of the catalyst particles using the three dimensional reconstructed image obtained by electron beam tomography (electron tomography) measurement using an STEM is performed, the ratio of the catalyst particles supported inside the mesopore is 50% or more.