Au containing mesostructured cellular foams NbMCF and ZrMCF in selective oxidation of methanol to formaldehyde

Mesostructured cellular foams (MCF) doped with Nb or Zr were used as matrices for preparation of gold catalysts for oxidation of methanol. The focus was on the characterisation of Au-NbMCF and Au-ZrMCF materials as well as the effect of Au-Nb or Au-Zr interactions and the gold particle sizes on the activity of MCF catalysts in the selective MeOH oxidation towards formaldehyde. The samples prepared were characterised by XRD, N-2 adsorption/desorption, TEM, UV-Vis, XPS, H-2-TPR, FT-IR combined with the adsorption of pyridine and test reaction. The results allowed defining the location and coordination of Nb and Zr in the structure of MCF, the state of gold on the surface as well as the acid/base properties of the catalysts obtained. The results showed that the bifunctionalised gold catalysts containing Nb and Zr are highly active in selective methanol oxidation in the temperature range 523-623 K. The presence of gold significantly enhanced the activity, whereas the Nb and Zr additives influenced the selectivity of the catalysts. Au-NbMCF and Au-ZrMCF appeared to be useful for the production of formaldehyde by methanol oxidation. (C) 2014 Elsevier B.V. All rights reserved.