- Reproducibility: Achieving consistent results can be difficult due to the sensitivity of catalysts to experimental conditions. - Deactivation: Catalysts may lose activity over time due to poisoning, sintering, or other deactivation mechanisms. - Scalability: Translating results from a lab-scale experiment to industrial-scale processes is not straightforward. - Complex Reaction Networks: Many catalytic processes involve multiple steps and intermediates, making the analysis more complicated.