| **Catalyst Type** | **Key Formulation** | **Operating Conditions** (Temp/Pressure) | **Energy Efficiency** | **Cost** | **Sensitivity to Impurities** | **Commercial Readiness** | | --------------------------------------- | ----------------------------------------------------------------------------------------------- | ---------------------------------------- | ------------------------------------------------------------------ | ------------------------------- | ------------------------------- | ------------------------------------ | | **Iron-Based** | Fused iron (Fe) promoted with oxides (K₂O, Al₂O₃, CaO) | 400–500 °C / 150–300 bar | High energy demand, well-proven process | Low (relative) | Moderate (tolerates some S, O₂) | Widely used in Haber-Bosch | | **Ruthenium-Based** | Ru on carbon or metal oxide supports (e.g., Ru/C, Ru/MgO), often Cs-promoted | 300–400 °C / 100–200 bar | Operates at lower temp/pressure, potentially more energy-efficient | High (Ru is expensive) | High (poisoned by S, O₂, H₂O) | Some industrial use, limited by cost | | **Advanced/Novel Catalysts** (Research) | Examples include electrides (C12A7:e⁻) supporting Ru, metal nitrides, or perovskite-type oxides | 300–400 °C / varied pressure | Potentially lower energy consumption and improved selectivity | Currently high due to R&D scale | Varies, often sensitive | Mostly pilot or R&D stage | ### Additional Notes on Key Metrics 1. **Operating Conditions**: Traditional iron-based catalysts typically require higher pressures and temperatures to achieve optimal activity, which translates to higher energy use. Ruthenium-based catalysts can often run at somewhat lower pressures and temperatures, saving energy but increasing capital costs. 2. **Energy Efficiency**: While iron catalysts are well-established and have been optimized for decades, ruthenium and novel catalysts may further reduce energy consumption if the issues of cost, availability, and stability are addressed. 3. **Cost**: Iron-based catalysts are relatively inexpensive. Ruthenium is a precious metal, so it carries a higher price tag. Novel catalysts, still in research phases, also tend to be costly due to specialized materials and limited manufacturing capacity. 4. **Sensitivity to Impurities**: Iron catalysts can handle moderate amounts of sulfur or oxygen impurities without severe deactivation, while ruthenium-based and many advanced catalysts are more easily poisoned, requiring cleaner feed gases. 5. **Commercial Readiness**: Iron-based catalysts are fully commercial, whereas ruthenium-based systems, though proven technically, remain limited by cost and sensitivity issues. Advanced catalysts show promise in labs and pilot projects but are not yet mainstream. [[Catalysts x Deep Tech Opportunities]]