Titanium species in deactivated HTS-1 zeolite from industrial cyclohexanone ammoxidation process

The effect of T-atom ratio and TPAOH concentration on the pore structure and titanium position in MFI-Type titanosilicate during dissolution-recrystallization process

“…The hydrophobic environment of the titanium in TS-1 allows for their application with water-based peroxides. With aqueous H2O2 as the oxidant, TS-1 has been widely used in phenol hydroxylation [2], epoxidation of propylene [3] and cyclohexanone ammoximation [4] reactions. Although TS-1 exhibits good activity in the oxidation of many organic compounds, their micropore size is about 0.55 nm, which implies reactants with a larger molecular size cannot penetrate the TS-1 channels and are restricted to interact only with the active sites on their external surface or at pore mouth.…”

Deactivation of solid catalysts in liquid media: the case of leaching of active sites in biomass conversion reactions

“…The presence of basic ammonia can dissolved the silica, and the framework Ti wasis transferred and precipitated as TiO 2 on the surface of the zeolite. 48 . The growing importance of the leaching phenomenon in 75 catalytic reactions can be perceived by the evolution of scientific documents documents published in this particular area, as shown by the data in Figure 1.…”

Environmental-Friendly Catalytic Oxidation Processes Based on Hierarchical Titanium Silicate Zeolites at SINOPEC

“…In addition, in our previous works, the irreversible deactivation of HTS zeolite has been investigated by using multiple characterization methods and catalytic evaluations [64][65][66]. It is confirmed that the dissolution of framework Si atoms and the removal of framework Ti atoms cause the formation of acidic amorphous TiO 2 -SiO 2 nanoparticles, leading to the inefficient decomposition of H 2 O 2 molecules during catalytic oxidation processes.…”