I. Tuzovskaya - Academia.edu (original) (raw)
Related Authors
Universidad Nacional Autónoma de México
Uploads
Papers by I. Tuzovskaya
Catalysis Communications, 2007
Different structural and electronic states of gold species in H-mordenite with SiO 2 /Al 2 O 3 mo... more Different structural and electronic states of gold species in H-mordenite with SiO 2 /Al 2 O 3 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 Au 3+ ions, charged clusters Au dþ n , and neutral nanoparticles Au m . 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).
Catalytic tests of the Au-zeolites pure or doped with Na revealed the existence of two types of a... more Catalytic tests of the Au-zeolites pure or doped with Na revealed the existence of two types of active sites of gold in CO oxidationpartly charged gold clusters Au dþ n (low-temperature activity) and gold nanoparticles Au 0 m (high-temperature activity). The data obtained demonstrates clear direct dependence of gold species reactivity on zeolite acid properties (Si/Al molar ratio and Na addition). Na modified Au-zeolites with different Si/Al molar ratio were found to be activated in CO oxidation in different degrees due to diverse redox state of supported gold species. The revealed effect of activation of one of two active species in CO oxidation ðAu dþ n Þ is promising for improvement of activity and stability of the gold-zeolites catalysts.
Catalysis Communications, 2007
Different structural and electronic states of gold species in H-mordenite with SiO 2 /Al 2 O 3 mo... more Different structural and electronic states of gold species in H-mordenite with SiO 2 /Al 2 O 3 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 Au 3+ ions, charged clusters Au dþ n , and neutral nanoparticles Au m . 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).
Catalytic tests of the Au-zeolites pure or doped with Na revealed the existence of two types of a... more Catalytic tests of the Au-zeolites pure or doped with Na revealed the existence of two types of active sites of gold in CO oxidationpartly charged gold clusters Au dþ n (low-temperature activity) and gold nanoparticles Au 0 m (high-temperature activity). The data obtained demonstrates clear direct dependence of gold species reactivity on zeolite acid properties (Si/Al molar ratio and Na addition). Na modified Au-zeolites with different Si/Al molar ratio were found to be activated in CO oxidation in different degrees due to diverse redox state of supported gold species. The revealed effect of activation of one of two active species in CO oxidation ðAu dþ n Þ is promising for improvement of activity and stability of the gold-zeolites catalysts.