The effect of gold on modern bimetallic Au-Cu/MWCNT catalysts for the oxy-steam reforming of methanol

Copper and gold doped copper catalysts supported on multi-walled carbon nanotubes were prepared by wet impregnation and deposition-precipitation methods, respectively. The catalysts were tested in the oxy-steam reforming of methanol (OSRM) and characterized by XRD, SEM-EDS, TOF-SIMS, thermo-gravimetric analysis and temperature-programmed desorption of ammonia. The reactivity results showed the promotion effect of gold on the activity and selectivity of the copper catalysts in the OSRM. The formed Cu-Au alloy as an active phase was responsible for the activity and selectivity improvement of the bimetallic catalysts in the oxy-steam reforming of methanol. The formation of an Au-Cu alloy was confirmed by the XRD, TOF-SIMS and SEM-EDS techniques. The reducibility and acidity of the tested catalysts are important factors, which influence the activity of the copper and gold-copper catalysts.