As for {HEAD ~ the noble metal eggshell catalyst} that may suitably be used as a layer of intermetallic diffusion barrier particles that is applied to the surface of the porous substrate, the noble metal eggshell catalyst is defined and described in great detail in {TAIL ~ U.S. Pat} 
As for { HEAD ~ the noble metal eggshell catalyst } that may suitably be used as a layer of intermetallic diffusion barrier particles that is applied to the surface of the porous substrate , the noble metal eggshell catalyst is defined and described in great detail in { TAIL ~ U.S. Pat }
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