Water-involved tandem conversion of aryl ethers to alcohols over metal phosphide catalyst

Catalytic Hydrolysis/Hydrogenolysis of Lignin-Derived Aryl Ethers over Bimetallic Pd-Ni Systems: The Directional Regulation of Reaction Pathways

“…The absence of DPE conversion in the inert gas atmosphere under catalysis of monometallic Pd/AC and bimetallic 3%Pd-1%Ni/AC demonstrates that H 2 is the active hydrogen source in the reaction process. It is in agreement with the experimental phenomena in previous literature studies. , The above difference in DPE conversion efficiency between different solvents and H 2 was due to the fact that the solubility of H 2 varied with solvent, which influenced the rate of H 2 transformation to active hydrogen. , For the fast H 2 transfer of isopropanol, a high conversion of DPE could be obtained. Only 3.6% of DPE was converted into CHPE at pressure of 0.1 MPa.…”

“…As listed in Figure a, the temperature-programmed reduction (TPR) patterns of 3%Pd/AC, 3%Pd-1%Ni/AC, and 3%Pd-3%Ni/AC exhibit a negative peak at about 117 °C, which is due to the fact that hydrogen is adsorbed on the elemental palladium at low temperature, causing hydrogen to spill out of the surface. ,, The phenomenon of spillover of H 2 from the surface did not appear in 1%Ni/AC and 3%Ni/AC, demonstrating a stronger H 2 adsorption capacity of the Pd-based catalysts. A reduction peak at 450 °C is the reduction of NiO of Ni/AC and Pd-Ni/AC .…”

“…H 2 activation and dissociation emerged in metal sites to generate adsorbed H atoms (Pd-H and Ni-H), when H 2 O adsorbed on the AC surface. Water from isopropanol formed OH*, and the OH* proceeded the hydrolysis of DPE or CHPE. , …”

“…The reductive hydrolysis process involves the first aromatic hydrogenation of DPE to CHPE, followed by a hydrolysis of CHPE to cyclohexanol and cyclohexanone. A small fraction of CHPE was cleaved to form cyclohexanol and cyclohexane. , The possible conversion pathways for DPE are summarized in Scheme . Therefore, it is imperative to develop specific catalysts to achieve directional control of the DPE reaction pathways to produce desired target products.…”

Integrated design of an amination process of lignin oxygenated model compounds to synthesize cyclohexylamine: catalyst nanostructure engineering and catalytic conditional strategy

“…Similarly, hydrogen dissociated on the surface of metal ruthenium nanoparticles could spill onto nickel, realizing the promotion of benzene ring hydrogenation at a lower temperature. 77 Zhao et al 78 proposed that ternary metal phosphides (Pd–Ni–P) could convert diphenyl ether to CHOL through the partial hydrogenation–reductive hydrolysis–hydrogenation pathway. Among them, the interaction between Pd and P elements leads to the electronic defects of Pd atoms, which promoted the partial hydrogenation of diaryl ethers with high selectivity.…”