An evaluation of potential hydrogen sulfide adsorbents for the protection of palladium catalyst in anaerobic culture systems

Hydrogen sulfide is produced by many anaerobic bacteria and can irreversibly damage the palladium catalyst used for oxygen removal in anaerobic jars and cabinets. The present study used direct measurements of oxygen concentration to quantify catalyst activity following exposure to H₂S and volatile fatty acids in the presence of eight potential H₂S adsorbents. Most adsorbents were unsatisfactory, but two compounds not tested previously afforded full protection against the effects of H₂S alone and provided protection in the presence of volatile fatty acids. The investigation demonstrated the importance both of selecting an adsorbent suitable for use in anaerobic conditions and of heating anaerobic jar catalysts in order to maintain activity.