Ammonia Synthesis over an Iron Catalyst with an Inverse Structure: A Comprehensive Review

Abstract

Ammonia synthesis is a cornerstone of the chemical industry, critical for fertilizer production and global food security. The Haber-Bosch process, relying heavily on iron-based catalysts, has been optimized over the decades. However, conventional catalysts still face limitations related to reaction conditions, energy efficiency, and catalyst deactivation. This review focuses on recent advances in inverse structured iron catalysts a novel configuration where the support encapsulates the active iron phase, reversing the conventional catalyst design. This inverse approach promises improved dispersion, enhanced surface properties, and increased resistance to sintering and poisoning. The review explores the synthesis methods, structural characterization, mechanistic insights, and catalytic performance of inverse iron catalysts, comparing them with traditional systems. Finally, it addresses current challenges and outlines future directions in the development of sustainable and efficient ammonia synthesis technologies.