A chelating agent, alizarin, was used to pretreat an aluminum surface before the electrochemical synthesis of polyaniline. Alizarin had two main effects on the process: (1) it suppressed the hydrogen evolution reaction and increased the current efficiency and (2) it stabilized the open-circuit potential in a corroding environment, such as in 0.1M NaCl. (C) 2003 Wiley Periodicals, Inc.