This invention introduces self-restructuring platinum-based ternary nanoalloy catalysts that maintain high oxidation activity after hydrothermal aging. By alloying Pt with two transition metals, the catalyst delivers durable low-temperature exhaust oxidation with reduced precious metal use, supporting efficient CO, hydrocarbon, and NO oxidation for cleaner combustion and regulatory compliance.
Background: Exhaust aftertreatment systems in combustion engines must oxidize CO, hydrocarbons, and NO under variable, steam-rich exhaust conditions. Conventional Pt or Pt–Pd catalysts require high platinum-group-metal loadings, light off at elevated temperatures, and suffer deactivation from sintering and phase segregation during hydrothermal aging. This degradation reduces NO-to-NO₂ conversion, diminishing downstream selective catalytic reduction (SCR) efficiency. A robust, low-temperature oxidation catalyst with sustained activity and lower precious metal content is needed to meet future emission standards across automotive, marine, and stationary applications.
Technology Overview: The catalyst consists of ternary alloy nanoparticles where platinum is alloyed with two transition metals such as Ni and Co or Mn and Fe, supported on refractory oxides including alumina, silica, zirconia, or titania. Nanoparticles 2–10 nm in size are synthesized via colloidal reduction, deposited, and calcined under controlled atmospheres to form uniform alloys confirmed by TEM–EDS and XRD analysis. The fresh catalyst surface is enriched in base metals and self-restructures into a Pt-rich core after aging at 800 °C in steam while maintaining homogeneous alloy distribution. This controlled restructuring preserves NO oxidation performance and stable CO and HC conversion in diesel oxidation (DOC) and three-way catalytic (TWC) systems.
Advantages: • Retains NO oxidation activity after severe hydrothermal aging • Uses lower platinum loading while achieving equal or better conversion than conventional Pt catalysts • Enables low-temperature light-off around 170–180 °C for earlier emissions control • Enhances NO-to-NO₂ conversion at 200 °C to improve downstream SCR performance • Maintains stable CO and HC oxidation comparable to commercial DOCs • Demonstrates excellent dispersion and stability through scalable wet-chemical synthesis
Applications: • Diesel oxidation catalysts and NO oxidation stages for on-road, non-road, marine, and locomotive engines • Three-way catalytic converters for gasoline engines requiring lower light-off and enhanced durability • Pre-SCR NO oxidation catalysts for heavy-duty diesel engines to stabilize NO₂ formation • Stationary and lean-burn generator emission control under variable load conditions • Marine and locomotive systems meeting IMO Tier III and Tier 4 Final standards • Retrofit and non-road modules requiring robust CO, HC, and NO oxidation under frequent aging cycles • Auxiliary power units and microturbines demanding fast light-off and long-life catalysts
Intellectual Property Summary: • United States – 18/873,049 – Utility – Filed 12/09/2024 – Published 01/28/2025 – Status: Filed
Stage of Development: Lab validated under simulated gas mixtures (CO, NO, hydrocarbons, O₂) with temperature ramps from 100 °C to 550 °C.
Licensing Status: This technology is available for licensing.
Licensing Potential: Ideal for automotive, marine, and stationary emissions control manufacturers seeking durable, low-temperature oxidation catalysts with reduced platinum-group-metal cost and superior long-term performance under high-temperature and humid exhaust conditions.
Additional Information: Hydrothermal aging test results, alloy characterization data, and detailed oxidation kinetics available upon request.
Inventors: Shiyao Shan, Shan Wang, Chuan Jian Zhong