A contaminant removal system is disclosed for selectively removing contaminants from a fluid stream. The contaminant removal system has a catalytic reactor of the type that is susceptible to deactivating agents, and is configured to remove contaminants from a fluid stream. The contaminant removal system has a first adsorbent device positioned upstream, with respect to the fluid stream direction, of the catalytic reactor, that is configured to chemically bind with and remove the deactivating agents from the fluid stream. The contaminant removal system can have a second adsorbent device positioned downstream, with respect to the fluid stream direction, of the catalytic reactor. The second adsorbent device is configured to remove undesirable byproducts that may be generated when the catalytic reactor removes contaminants from the fluid stream.