Use of Bimetallic Catalysts for Ethyne Hydrogenation

Industrial practice will clearly favour low metal loadings, and it is to be expected that it will be difficult to achieve conjunction of two (or more) components when their surface concentrations are small nevertheless there are strong indications that they are successfully made and used, at least in some installations. Methods for preparing bimetallic catalysts have been reviewed in depth, and the merits of employing organometallic complexes containing two elements have been emphasised. The cost of large-scale manufaeture by sueh a method may however 

The best-known metallic promoter is lead. This has long been known in the shape of the Lindlar which is PdPb/CaCOs together with 

The selective performance of platinum is raised by the addition of rhenium, and admixing with copper or gold helps even that of iridium.  

The poisoning of PCI/AI2O3 by mercury vapour is a complex phenomenon that has been fully investigated activity for ethene hydrogenation was suppressed while that of ethyne remained, so that improved selectivity resulted. Other metals examined in less detail showed similar behaviour. 

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