Varadwaj Pradeep R, Marques Helder M, Grabowski Ireneusz
Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg 2050, South Africa.
Institute of Physics, Faculty of Physics, Astronomy, and Informatics, Nicolaus Copernicus University in Toruń, 87-100 Toruń, Poland.
Int J Mol Sci. 2025 May 13;26(10):4670. doi: 10.3390/ijms26104670.
Ammonia synthesis remains a cornerstone of global chemical manufacturing, essential for fertilizer production, energy storage, and emerging carbon capture technologies. This overview examines recent developments in the understanding of elementary reaction mechanisms in heterogeneous catalysis, with emphasis on transition metal thermocatalysts operating under the Haber-Bosch process. Traditionally, the dissociative adsorption of nitrogen (N) has been considered the rate-determining step. However, recent studies challenge this view, revealing possible shifts in rate-determining steps and suggesting that alternative mechanistic pathways may be operative. The discussion critiques studies that adhere strictly to the classic dissociative mechanism-often inferred from the reaction order of N-while overlooking alternative pathways that could offer more efficient catalytic routes and deeper mechanistic insight into ammonia synthesis. These insights offer a pathway toward more rational catalyst design and improved process efficiency in ammonia synthesis.
氨合成仍然是全球化学制造的基石，对肥料生产、能量存储和新兴的碳捕获技术至关重要。本综述考察了多相催化中基元反应机理认识方面的最新进展，重点关注在哈伯-博施法（Haber-Bosch process）下运行的过渡金属热催化剂。传统上，氮（N）的解离吸附被认为是速率决定步骤。然而，最近的研究对这一观点提出了挑战，揭示了速率决定步骤可能发生的变化，并表明可能存在其他起作用的反应机理途径。讨论对那些严格遵循经典解离机理（通常从氮的反应级数推断而来）的研究提出了批评，同时忽略了那些可能提供更高效催化途径以及对氨合成有更深入机理认识的替代途径。这些见解为氨合成中更合理的催化剂设计和提高工艺效率提供了一条途径。
