The influence of fullerenes and related support materials on the structural and catalytic properties of ruthenium was investigated. Catalysts based on Cao, raw fullerene black, extracted fullerene black, cathode deposit and graphite were prepared by an impregnation/activation procedure with Ru3CO12. The local co-ordination sphere of the resulting highly dispersed X-ray amorphous ruthenium was investigated by means of EXAFS. The dominating role of the presence of non-six-membered carbon rings on the structure and the stability of the Ru particles will be illustrated.