The adsorption of urea on Au(100) and Au(111) electrode surfaces was studied through a combination of cyclic voltammetry and Fourier-transform infra-red spectroscopy. The infra-red spectra indicate that urea molecule is adsorbed on Au(100) with a molecular plane normal to the electrode surface. On Au(111), urea showed a different coordination. Lifting from 5x20 to 1x1 on the Au(100) surface was accelerated by the adsorption of urea. The kinetics of the 5x20 to 1x1 transition was monitored by a time-resolved IRAS measurement. The lifting of a reconstructed 5x20 surface to 1x1 proceeded within 20s. However, the reconstruction from the 1x1 to 5x20 surface, required a longer period of time, more than 70s.