Researchers at the Fritz Haber Institute of the Max Planck Society, together with the Max Planck Institute for Chemical Energy Conversion and Clariant, have uncovered new insights into the complex catalyst systems driving industrial ammonia production.

Key Findings:

• Catalyst Activation: The activation stage is crucial, as it forms the active catalyst configuration.

• Promoter Role: Promoters such as potassium, calcium, and aluminum oxides create cement-like phases that boost activity, stability, and longevity. Their spatial distribution within the catalyst is vital for efficiency.

• Structural Insights: The active catalyst is a porous form of iron, covered by mobile potassium species that act as reaction pacemakers.

• Stability Factors: Mineral phases containing oxides of aluminum, silicon, and calcium stabilize the catalyst’s hierarchical porous structure, ensuring durability and resistance to deactivation.

Using advanced techniques such as operando scanning electron microscopy and near-ambient pressure X-ray photoelectron spectroscopy, the team decoded how promoters and structural transformations enhance catalyst performance.

Prof. Thomas Lunkenbein emphasized that this deeper mechanistic understanding will guide the design of next-generation ammonia catalysts that are both more effective and sustainable.

These findings build on the institute’s long tradition of excellence in ammonia research from Fritz Haber’s Nobel Prize in 1918 for synthesizing ammonia, to Gerhard Ertl’s 2007 Nobel Prize for advancing the understanding of catalytic reactions. Today’s work continues that legacy, offering a clearer view of how multi-promoted catalysts sustain the Haber-Bosch process, which remains central to global fertilizer production after more than a century.

Source: https://www.fhi.mpg.de/2129835/2025-09-22-Behind-the-scenes-of-ammonia-synthesis