In this work, characterizations using X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) confirm that argon glow discharge plasma can effectively reduce the Al2O3 supported Ir catalyst without the use of any conventional reducing chemicals. Such plasma-reduced Ir/Al2O3 catalyst shows a significantly enhanced dispersion. High conversions have been achieved on this plasma-reduced Ir/Al2O3 catalyst for CO2 reforming of methane.