Ultrafine Platinum Catalysts for Hydrogen Fuel Cells (Case No. 2023-026)
Ultrafine platinum (Pt)-based catalysts present a promising avenue for achieving exceptional fuel cell activity while minimizing base transition metal content. Decreasing the levels of base metals reduces leaching and associated cation poisoning, thereby ensuring robust fuel cell stability. Conventional Pt-based catalysts exhibit non-uniform size distribution and elevated base transition metal content. Additionally, the current fabrication procedures for these catalysts are encumbered by both substantial costs and time-intensive processes. Hence, the pursuit of an innovative and cost-efficient synthesis methodology is needed to generate Pt-based nanoparticle catalysts that foster high fuel cell activity and high stability.
Researchers from the Department of Materials Science and Engineering have developed a novel synthetic method for uniformly distributed ultrafine Pt-based catalyst with ultralow base transition metal-oxide content. The performance of the catalysts was evaluated in membrane electrode assemblies, where they showed significant improvement in oxygen reduction reaction mass activity compared to commercial Pt-based catalysts. The durability and power performance of the fuel cell catalysts surpasses the targets set by US Department of Energy. Publication: Embedded oxide clusters stabilize sub-2 nm Pt nanoparticles for highly durable fuel cells
Potential Applications:
- Fuel Cells
- Electric Vehicles
- Electronics
- Medical Devices
Advantages:
- High catalytic performance
- Significant improvement in durability
- Low voltage and power loss
- Ultralow transition metal oxide content
Ion-Conductive and Electron-Conductive Open Lattice Catalyst Support Framework (Case No. 2025-090)
Proton-exchange membrane fuel cells (PEMFCs) are promising technologies for clean energy applications due to their high efficiency and reduced emissions. These devices consist of catalyst layers that facilitate chemical reactions that convert hydrogen and oxygen into water and electricity. Traditional fuel cells consist of platinum on carbon supports with ionomers that act as proton-conductive binders. Existing fuel cells are limited by increased oxygen transport resistance due to reduced oxygen diffusion and increased costs due to the use of high platinum loadings. Conventional systems often suffer from poor operational stability, which limits their long-term durability. In addition, the polymer membrane used in conventional PEMFC systems is expensive to manufacture, only works at lower temperatures, and has raised environmental concerns. There remains an unmet need for an affordable proton-exchange membrane fuel cell with increased durability and efficiency.
UCLA researchers from the Department of Materials Science and Engineering have developed a novel design for proton-exchange membrane fuel cells. The innovative design integrates an open lattice catalyst support framework that possesses ion-conductive and electron-conductive properties. Ionic groups are grafted onto carbon nanotube bundles, which eliminates the need for ionomers in the catalyst layer. The innovative dual conductivity design facilitates direct access for protons, oxygen and electrons, minimizing mass transport resistance and enhancing fuel cell performance. This novel design provides improved power output better mass transport, and good performance over a wide temperature range. The reported cell design can revolutionize the development of proton-exchange membrane fuel cells by providing enhanced performance and output.
Potential Applications:
• Proton-exchange membrane fuel cells (PEMFCs)
• Electrolyzers
• Stationary power generation systems
• Portable power systems
• Hydrogen-powered industrial equipment
• Aerospace and military fuel cell systems
• Anion-exchange membranes for energy devices
• Next-generation energy storage and conversion systems
Advantages:
• Simultaneous ion and electron conductivity
• Reduced oxygen transport resistance
• Enhanced mass transport efficiency
• Increased power output
• Lower platinum loading requirements
• Significant cost reduction in PEMFCs
• Improved durability and stability
Protected Ultrafine Catalysts, Including Pt-Based Catalysts for Fuel Cell Applications (Case No. 2021-295)
Platinum catalysts are essential for use in hydrogen fuel cell technologies to cleanly and efficiently produce electricity. Traditional platinum catalysts are generally stable but require large quantities of expensive platinum group metals to achieve the necessary surface area required for use in fuel cells. Ultrafine nanocatalysts can reduce the amount of platinum used while maintaining high electrochemical surface area (ECSA) and high material utilization. However, ECSA can be easily damaged by the environment limiting their usability. Protective layers can alleviate the damages but reduce the performance of the catalyst. There is a need for ultrathin protective layers that can protect these nanocatalysts without limiting their function.
UCLA researchers in the Department of Materials Science and Engineering developed a strategy to uniformly introduce and mix metal precursors with ultrathin carbon support. The developed composition of metal catalysts and the protective layers were evaluated with a fuel cell membrane electrode assembly where they showed significant improvements in oxygen reduction mass activity compared to existing commercial electrodes. Furthermore, it also showed improved durability and required less platinum than existing platinum catalysts.
Potential Applications:
- Fuel cells
- Chemical synthesis
- Electrochemistry
Advantages:
- Long lasting performance
- Easy to Produce
- High catalytic performance
High Performance Platinum-Based Catalyst Combined with Carbon Support Engineering (Case No. 2019-469)
UCLA researchers have invented a type of highly stable and active materials Pt-based alloy loaded on a novel carbon support, which is developed through carbon engineering. The fuel cell performance of the catalysts is significantly improved, leading to mass activity values above the DOE target. The material design is innovative; simple in term of synthesis and preparation; and stable enough to be stored at room temperature. This novel method of design and manufacturing on Pt-based alloys on novel carbon-support structures could allow the development cost-effective and efficient fuel cells to be used as portable power generators.
Potential Applications:
- Fuel cells
- Heterogeneous catalysis
- Portable power generation
- Transportation fuel (motor vehicles)
Advantages:
- Simple preparation
- Stable composites
- High mass activity
- Low cost
Fuel Cell With Dynamic Response Capability Based On Energy Storage Electrodes (Case No. 2017-231)
Current fuel cell technologies are limited by cost and lifetime, as well as poor response to operating condition fluctuations. Adding energy storage devices to fuel cells can improve their dynamic response, reduce performance degradation, and decrease fabrication cost, but designing energy management systems is complex, energy storage devices occupy the limited room available while increasing costs, and many energy storage materials cannot tolerate the acidic conditions in many fuel cells. Therefore, integrating energy storage into existing fuel cell components has the potential to deliver the desired operational improvements and reduce the power system size and cost.
UCLA researchers have developed fuel cell electrodes with energy-storage capabilities that can provide significantly improved power responsiveness. The design provides fuel cells with supercapacitor-like response to transient loads, while reducing size and cost. Fuel cells with this innovation also demonstrate high durability under harsh operating conditions, resulting in prolonged lifetimes, and possess outstanding electron and proton conductivity, extraordinary energy-storage capability, and cycling stability. These electrodes can be used in different types of fuel cells, including proton exchange membrane, solid acid, and solid oxide. The technology is especially useful in automotive applications, where frequent acceleration places fluctuating demand on fuel cells, and is an attractive low-cost, highly reliable solution for distributed power generation and other applications.
Potential Applications:
- Automotive
- Portable technologies
- Distributed generation
- Consumer electronics (laptops, smartphones, etc.)
Advantages:
- Improved power responsive capabilities
- Space savings
- Reduced cost
- High durability under harsh operating conditions
- All-in-one power supply in electric vehicles
Gas Fill-Up Process System and Methodology with Minimum and/or No Cooling (Case No. 2014-054)
Professor Manousiouthakis and colleagues have developed a novel system and method of filling vehicle tanks with gaseous fuels that eliminates the need for expensive cooling systems. The technology can be applied to hydrogen fueling stations and other high-pressure gas fueling stations, such as those used with natural-gas powered vehicles. The technology also offers faster fill-up times than conventional technology.
Potential Applications:
- FCEVs and natural gas vehicles
- High-pressure storage tanks
Advantages:
- Reduces or eliminates costs for cooling systems
- Provides faster fill-up times
- Improves system safety
Highly Durable and Active Fuel Cell Electro-Catalyst Designed With Hybrid Support (Case No. 2012-559)
Precious metal group (PMG) nanocrystals (NCs) (e.g. Pt, Pd, and Au) have shown great potential as cathode electrocatalysts in proton exchange membrane (PEM) fuel cells. To synthesize highly active PMG nanocatalysts in a cost-effective manner, PMG NCs are usually loaded on high surface area supporting materials, such as carbon-based materials. Graphene, or reduced graphene oxide (RGO), stands out as an excellent electrocatalyst support because of its good conductivity, high surface area, and high mechanical strength. However, the stacking effect between RGO sheets blocks a substantial amount of catalytic sites on NCs and sets a higher resistance for the diffusion of reactant molecules, which in turn retards the catalytic reaction. There have been reports of retarded oxygen reduction rates at a certain potential range and slowed oxygen diffusion using RGO as a catalyst support for the oxygen reduction reaction (ORR) occurring at the fuel cell cathode. Additionally, RGO sheets obtained by wet chemical synthesis usually contain more defects, which reduce the electron transfer rate in the graphene sheet and across the NC RGO interface as well. Therefore, further improvement of the design is necessary for mitigating or preventing the stacking of RGO sheets as the electrocatalyst support.
Researchers at UCLA have designed a system incorporating a highly active and durable ORR catalyst supported by an hybrid composite material that is prepared by loading Pt NCs on a primary support RGO, which is then composited with a secondary high surface area carbon black (CB) support. With the insertion of CB particles between the Pt RGO sheets, stacking of RGO is effectively prevented, promoting diffusion of oxygen molecules through the RGO sheets and enhancing the ORR electrocatalytic activity. The resulting hybrid structure also exhibits improved durability, with >95% retainment of Pt’s electrochemical surface area after 20,000 operation cycles as measured by the accelerated durability test.
Potential Applications:
- Broadly applicable to both cathode and anode catalysts in hydrogen fuel cells, direct methanol fuel cells, and metal fuel cells.
Advantages:
- Minimized stacking of RGO
- Enhanced electrocatalytic activity
- Improved durability