PROTECTION OF RH/AL2O3 CATALYSTS BY POTASSIUM FUNCTIONALIZATION OF THE AL2O3 SUPPORT

It has been found that the exchange functionalization of isolated Al-OH groups with K+ to produce Al-OK groups provides a method for the stabilization of Rh/Al2O3 catalysts against Rh(I) formation. K2CO3 was employed for functionalization, and the thermal decomposition of the CO3(2-) anion (T < 870 K) was studied along with the effective and preferential removal of isolated Al-OH groups, producing Al-OK species. Rh/K-Al2O3 catalysts are shown to be stable against Rh(x)0 degradation in the presence of CO(g). The Al-OK functionalization procedure is effective in preventing Al-OH re-formation under extreme hydrolysis conditions up to 770 K. This procedure may lead to effective practical methods for the protection of Rh environmental catalysts against loss of catalytic activity due to Rh(x)0 degradation.