CO and VOCs Catalytic Oxidation Over Alumina Supported Cu–Mn Catalysts: Effect of Au or Ag Deposition

Alumina supported Cu–Mn mixed oxide with Cu/Mn molar ratio 2:1 was used as a support of gold and silver catalysts for oxidation of CO, methanol and dimethylether. Different techniques (XRD, HRTEM, XPS, FTIR, EPR, and TPR) were used to investigate structure–reactivity relationship. A strong effect of the nature of the promoters on the catalytic behaviour was observed. Superior catalytic activity in oxidation of CO was measured after addition of Au, while modification by Ag affected very slightly the CO oxidation activity of Cu/Mn 2:1 sample. Both Au and Ag have beneficial effect on CH3OH oxidation activity of Cu–Mn mixed oxides. The combination of the good redox properties of Cu–Mn mixed oxides and gold nanoparticles has proved to be an advantageous approach for developing new catalytic formulations with high effectiveness to eliminate different type pollutants in waste gases from formaldehyde production. The use of high surface area support is beneficial for the stabilization of gold particles in a highly dispersed state and contributes for economic viability in case of practical applications, because of the composition of this catalytic system, that is mostly alumina (80 %).