In this paper, the dealloying of single-phase Al2Au ribbons and morphological evolution of nanoporosity have been investigated in different inorganic and organic acid solutions. The results demonstrate that the acid strength coupled with the nature of acid anions can significantly influence the dealloying velocity, adatom diffusion and morphological evolution of the resultant nanoporous Au. Compared with those in inorganic acids, the dealloying velocities can be greatly reduced in organic carboxylic acids and severe passivation is prone to occur. The underlying mechanism of passivation occurring at the dealloying front in the organic acids has also been discussed. (C) 2012 Elsevier B. V. All rights reserved.