• Innovative Approach: APE refines traditional Kinetic Monte Carlo (kMC) simulations by dynamically updating process lists, reducing bias and uncovering overlooked atomic movements.
• Significant Findings: The application of APE to Pd surfaces revealed nearly 3,000 processes, highlighting complex atomic motions previously undetected.
• Real-World Impact: Insights from APE can lead to the development of more efficient catalysts, crucial for energy production and pollution control. This implies applications in areas like automotive catalytic converters, which are used in cars to reduce emissions.
• Machine Learning Integration: APE utilizes machine-learned interatomic potentials (MLIPs) to predict atomic interactions, enhancing the accuracy of simulations.
Kinetic Monte Carlo (kMC) simulations are essential for studying the long-term evolution of atomic and molecular processes. They are widely used in fields like surface catalysis, where reactions on material surfaces are crucial for developing efficient catalysts that accelerate reactions in energy production and pollution control. Traditional kMC simulations rely on predefined inputs, which can limit their ability to capture complex atomic movements. This is where the Automatic Process Explorer (APE) comes in.
Developed by the Theory Department at the Fritz Haber Institute, APE overcomes biases in traditional kMC simulations by dynamically updating the list of processes based on the system's current state. This approach encourages exploration of new structures, promoting diversity and efficiency in structural exploration. APE separates process exploration from kMC simulations, using fuzzy machine-learning classification to identify distinct atomic environments. This allows for a broader exploration of potential atomic movements.
By integrating APE with machine-learned interatomic potentials (MLIPs), researchers applied it to the early-stage oxidation of Palladium (Pd) surfaces, a key system in pollution control. When applied to the early-stage oxidation of a Palladium (Pd) surface, a key material used in catalytic converters for cars to reduce emissions, APE uncovered nearly 3,000 processes, far exceeding the capabilities of traditional kMC simulations. These findings reveal complex atomic motions and restructuring processes that occur on timescales similar to molecular processes in catalysis.
The APE methodology provides a detailed understanding of Pd surface restructuring during oxidation, revealing complexities previously unseen. This research enhances our knowledge of nanostructure evolution and its role in surface catalysis. By improving the efficiency of catalysts, these insights have the potential to significantly impact energy production and environmental protection, contributing to cleaner technologies and more sustainable industrial processes.
Physical Review Letters
10.1103/PhysRevLett.134.096201
Automatic Process Exploration through Machine Learning Assisted Transition State Searches
4-Mar-2025