An understanding of the relationship between the chemistry and structure of rhodium surfaces with their catalytic performance has already been gained from extensive surface spectroscopic investigations. Now, researchers at the University of Pittsburgh, Pennsylvania, have studied the protection of rhodium supported catalysts by potassium functionalisation, in connection with their performance in syngas-related industrial reactions and in automobile exhaust gas converters (M. I. Zaki, T. H. Ballinger and J. T. Yates, J. Phys. Chem., 1991, 95, (10), 4028-4033).

They found that the exchange functionalisation of isolated aluminium-hydroxide groups of the alumina support by potassium carbonate modifier produced aluminium-oxygen potassium groups which stabilise the rhodium/alumina catalysts against rhodium(I) formation.

The functionalisation could thus produce an effective practical method for the protection of environmental rhodium catalysts against loss of catalytic activity due to rhodium(0) degradation.