Well-formed, size-controlled ruthenium nanoparticles active and stable for acetic acid steam reforming

Mg(Al)O supported Ru and Rh catalysts with low loading of active metal (0.5wt.%) were tested in the steam reforming (SR) of acetic acid (AA) to hydrogen rich mixtures. Two synthetic procedures were adopted to deposit metal nanoparticles on support material: conventional impregnation from metal chlorides aqueous solutions and size-controlled metal nanoparticles (SCMNPs) deposition method. SCMNP derived Ru catalysts showed good performances fully comparable to standard Rh based systems. After 20h t.o.s. at reaction temperature of 700°C, steam-to-carbon ratio of 3 and weight hourly space velocity of 6h^-1, Ru catalysts showed 100% conversion and hydrogen yield higher than 70%. The presence of well formed metal nanoparticles and the residual hydrotalcite present in the support play a determinant role in limiting the deactivation by coke deposition and by nanoparticles sintering.