Different structural and electronic states of gold species in H-mordenite with SiO2/Al2O3 molar ratio 206 and their transformations under redox treatments have been studied by the methods of diffuse reflectance UV-visible spectroscopy and FTIR spectroscopy of adsorbed CO. Different states of ionic and metallic gold were detected in the zeolite channels and on the external surface of the zeolite - Au+ and Au3+ ions, charged clusters Aunδ +, and neutral nanoparticles Aum. Catalytic tests of the samples revealed the co-existence of several types of active species of gold in CO oxidation - gold clusters <1.5 nm (responsible for low-temperature activity) and gold nanoparticles (responsible for high-temperature activity).
ASJC Scopus subject areas
- Process Chemistry and Technology