Oxidation of Benzene to Phenol with Hydrogen Peroxide Catalyzed by a Modified Titanium Silicalite (TS-1B)

Direct cyclohexanone oxime synthesis via oxidation-oximization of cyclohexane with ammonium acetate

An unexpected cascade reaction for oxidation-oximization of cyclohexane with ammonium acetate was developed for the first time to access cyclohexanone oxime with 50.7% selectivity (13.6% conversion). Tetrahedral Ti sites in Ni-containing hollow titanium silicalite can serve as bifunctional catalytic centers in the reaction. This methodology not only provides a direct approach to prepare cyclohexanone oxime, but also simplifies process chemistry. Various available nitrogen sources, such as ammonium salt and even ammonia can be used as starting materials.

Direct synthesis of phenol by novel [FeFe]-hydrogenase model complexes as catalysts of benzene hydroxylation with H2O2

Compared the catalytic performance of complexes 1–3, the complex 2 has the highest phenol yield (24.6%) and phenol selectivity (92%), which has the highest electron densities of the catalytically active sites.

Periodic mesoporous organosilicas functionalized with iron(iii) complexes: preparation, characterization and catalysis on direct hydroxylation of benzene to phenol

Incorporation of iron(iii) complexes into hydrophobic periodic mesoporous organosilica prevents over-oxidation of phenol and hence significantly improves both the selectivity and yield of phenol compared with their corresponding homogeneous iron precursors.

Zeolite science and technology at Eni

This article reviews the results obtained in the synthesis, characterization and applications of zeolites and related microporous materials, focusing on catalytic processes developed in Eni research laboratories over the last 40 years.

Synthesis of a highly active oxidation catalyst with improved distribution of titanium coordination states

A facile strategy was carried out to construct a high-performance titanosilicate oxidation catalyst with optimized distribution of titanium coordination states.

Structure of the Active Platinum Cluster and Reaction Pathway of the Selective Synthesis of Phenol from Benzene and Oxygen Regulated with Ammonia on a Platinum Cluster/β-Zeolite Catalyst Studied by DFT Calculations

DFT calculations were used to investigate the structure of the active Pt cluster and the catalytic reaction pathway for the selective synthesis of phenol from benzene and molecular oxygen regulated with ammonia on a Pt cluster/β-zeolite catalyst that was reported to be active for the selective hydroxylation of benzene only in the coexistence of ammonia. It was found that Pt5-Pt6 clusters were active for the direct synthesis of phenol, and they provided the reaction sites for bond rearrangements among ammonia, oxygen, and benzene; furthermore, the coexistence of ammonia was crucial for the selective oxidation of benzene to phenol, as it suppressed benzene combustion to CO2 and promoted the selective synthesis of phenol. It was further found that water coexisting in the system also played a significant role in desorbing phenol on the Pt cluster surface, which resulted in promotion of the overall selective synthesis of phenol. The energy diagram for the reaction sequences and the structures of the transition states were obtained, which indicated the origin of the Pt/β catalysis.

Iron(iii) complexes of multidentate pyridinyl ligands: synthesis, characterization and catalysis of the direct hydroxylation of benzene

Correlation between the electrochemistry and catalytic performance of multidentate pyridinyl iron complexes in the hydroxylation of benzene suggests that more electron-donating ligands are beneficial for catalysis.