$\ce{Ru(OH)_x}$/support catalysts can be prepared by the immobilization of $\ce{RuCl3}$(or $\ce{RuCl3·nH2O}$) on support ($\ce{Al2O3, TiO2, Fe3O4}$) in aqueous medium, and subsequent treatment with $\ce{NaOH}$ (1 M) until the pH is around 13. The mixture is stirred for 1 day, filtered, washed with water, and dried in vacuo. $\ce{Ru(OH)3}$ is easily prepared as a black precipitate by adding a slight excess of a sodium hydroxide solution to a hot aqueous solution of ruthenium chloride ($\ce{RuCl3}$).
Ref.: Bhattarai, D., Lee, J.-h. and Keum, G. (2013). Ruthenium hydroxide. In Encyclopedia of Reagents for Organic Synthesis, (Ed.). DOI: 10.1002/047084289X.rn01593