Revolutionizing Ammonia Synthesis: FeCoNiAlSi High-Entropy Alloy Catalyst for Low-Pressure, Low-Temperature Applications
Yidi Shen, Luca Sementa, D. D. Johnson, Alessandro Fortunelli, Qi An, William A. Goddard
Abstract
The Haber-Bosch (HB) process, critical for global ammonia production, is hindered by its high energy consumption and operational demands, requiring extreme pressures and temperatures. Developing catalysts that reduce these demands while maintaining practical efficiency is essential for achieving sustainable ammonia synthesis. Here, we investigate the FeCoNi(AlSi) 0.76 high-entropy alloy (HEA) as a catalyst for the HB process using quantum mechanics (QM) and kinetic Monte Carlo (kMC) simulations. Mechanistic analysis revealed significantly lower reaction barriers compared to pure Fe, and kMC simulations predict an NH 3 turnover frequency (TOF) that is 65 times higher than pure Fe under industrial conditions. Under reduced pressure (21 atm) and moderate temperature condition (673 K), the HEA retained half the NH 3 production rate of pure Fe at extreme industrial conditions, revealing its potential to reduce energy and pressure requirements. This study demonstrates the promise of HEAs in enabling more energy-efficient and sustainable ammonia production technologies.