A Rh/SiO2 catalyst with excellent activity and stability for ethylene hydroformylation was developed by modifying with tethered diphenylphosphinopropyl and doped with an Al promoter. The catalyst was characterized by means of N-2 adsorption/desorption isotherms, transmission electron microscope, NH3 temperature programmed desorption, Fourier transform infrared spectroscopy and solid-state nuclear magnetic resonance. Experimental results showed that the existence of the Al promoter inhibited the growth of Rh particles, increased the number of exposed Rh atoms, changed the acidity of the catalyst surface, promoted in situ formation of active species that were similar to their corresponding homogeneous counterparts, and enhanced electron density of the P atom in the phosphine ligand. (C) 2014 Elsevier B.V. All rights reserved.