Aqua regia activated Au/C catalysts for the hydrochlorination of acetylene

► Impregnated Au/C catalyst with aqua regia as a solvent displayed superior activity in the hydrochlorination reaction of acetylene to vinyl chloride monomer. ► A synergistic effect between HCl and HNO3 is present, driving the Au nanoparticles nucleation process over the carbon support. ► The impregnating acid mixture can affect the carbon support enriching the presence of oxygen functional groups. ► The reaction occurs over Au3+ centres at the Au/C interface.