In this study, polypyrrole (PPy) was deposited on the surface of multiwall carbon nanotubes (MWCNTs), and PPy-MWCNTs were used to support the AuCl3 catalyst. Transmission electron microscopy and Fourier-transform infrared spectrometry confirmed the presence of PPy species in AuCl3/PPy-MWCNT catalysts. AuCl3/PPy-MWCNTs displayed enhanced catalytic activity and stability for acetylene hydrochlorination compared to AuCl3/MWCNT. Electron transfer may occur between the N atom of PPy and the Au3+ center, which affects the adsorption of hydrogen chloride during acetylene hydrochlorination. Crown Copyright (c) 2013 Published by Elsevier B.V. All rights reserved.