The preparation of Ru nanoparticles supported on gamma-Al2O3 followed by chemical reduction using RuCl3 as a precursor is demonstrated, and their properties are compared to Ru nanoparticles supported on gamma-Al2O3 prepared by impregnation of gamma-Al2O3 with Ru-3(CO)(12) and subsequent thermal decomposition. The Ru nanoparticles resulting from chemical reduction of RuCl3 are slightly larger (1.2 vs. 0.8 nm). In addition, Ru nanoparticles were deposited on Stober SiO2 using both deposition techniques. These particles were larger than the ones deposited on gamma-Al2O3 (2.5 and 3.4 nm for chemical reduction and thermal decomposition, respectively). Taking into account the size differences between the Ru nanoparticles, all catalysts display similar activity (0.14-0.63 mol center dot g(Ru)(-1)center dot h(-1)) and selectivity (>= 99%) in the sunlight-powered Sabatier reaction. Ergo, the use of toxic and volatile Ru-3(CO)(12) can be avoided, since catalysts prepared by chemical reduction of RuCl3 display similar catalytic performance. ; This research was funded by the European Commission (H2020 project SPOTLIGHT, grant no. 722788).