Bimetallic transition metal phosphide catalysts are promising materials for low-temperature, liquid-phase hydrogenation reactions. This work explores the chemoselective hydrogenation ability of RuMoP using various functionalized aromatic hydrocarbons to provide insight into how the functional groups compete for reduction on the surface of RuMoP. Using molecular hydrogen as the reductant, high selectivity (similar to 99%) to reduction of the substituent is achieved for the hydrogenation of electron withdrawing functionalities such as nitrobenzene, benzaldehyde, and benzophenone with RuMoP to yield aniline, benzyl alcohol, and diphenylmethanol, respectively. In contrast, aromatics with electron donating groups such as phenol, anisole, and toluene, show high ring hydrogenation selectivity (similar to 99%) to form cyclohexanol, methoxycyclohexane, and methyl cyclohexane, respectively, although the reaction proceeded slowly with RuMoP. Pyridine adsorption was studied via diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), which provided evidence of surface electron deficient sites (i.e., Lewis acids) that are responsible for targeting the electron-rich portion of the substrate. Additional DRIFTS experiments were performed using nitrobenzene, anisole, and a mixture of the two. From these experiments, features associated with -NO2 adsorption in nitrobenzene and ring adsorption in anisole were observed, which correlated well with the observed reaction results. Finally, a solvent study provided evidence for the competitive adsorption of isopropanol and the pi-electrons from the aromatic ring of phenol with the former being more favorable on RuMoP surface.