25012-93-5Relevant articles and documents
Palladium-based bifunctional membrane reactor for one-step conversion of benzene to phenol and cyclohexanone
Sato, Koichi,Hamakawa, Satoshi,Natsui, Mayumi,Nishioka, Masateru,Inoue, Tomoya,Mizukami, Fujio
, p. 276 - 281 (2010)
On the one-step hydroxylation of benzene to phenol over a Pd membrane reactor, the bifunctional effects between Pd membrane and metal particles were investigated. In this reaction system, the active oxygen species are formed by the reaction with the permeated hydrogen and adsorbed oxygen over Pd membrane. The active oxygen species are reacted with benzene and directly converts into phenol. For improving this system, various active metals were loaded on the α-Al2O3 porous tube which was the substrate of the thin Pd membrane. The loading of noble metals resulted in the enhancement of the activity of side reactions, i.e., complete oxidation and hydrogenation, and a decrease in the hydroxylation activity. The negative effect on hydroxylation was due to the imbalance between the catalytic activities of highly dispersed noble metal particles and the Pd membrane, which has a relatively small surface area. In contrast, the loading of Cu suppressed complete oxidation and enhanced the hydroxylation activity. This effect was mainly due to the increase in the hydrogenation activity without significant acceleration of oxidation. In addition, the potential for the selective conversion of benzene to cyclohexanone by this reactor was discussed.
Synergies of surface-interface multiple active sites over Al-Zr oxide solid solution supported nickel catalysts for enhancing the hydrodeoxygenation of anisole
Fan, Guoli,Li, Feng,Lin, Yanjun,Yang, Lan,Zhang, Yaowen
, (2022/01/19)
Currently, the catalytic hydrodeoxygenation (HDO) of oxygen-containing compounds derived from biomass to highly valuable chemicals or hydrocarbon bio-fuels is attracting more and more attention. Concerning the design and synthesis of high-performance supported metal catalysts for HDO, the efficient deposition/immobilization of active metal species on supports, as well as the construction of the favorable properties of supports, is quite necessary. In this work, we fabricated series of aluminum-zirconium oxide solid solution supported Ni-based catalysts by a simple surfactant-assisted homogeneous coprecipitation and applied them in the HDO of anisole. Various structural characterizations showed that surface-interface properties of Ni-based catalysts (i.e., surface acidity, defective structures, and metal-support interactions) could be finely tuned by adjusting the amount of Al introduced into Al-Zr oxide solid solutions, thus profoundly governing their catalytic HDO activities. It was demonstrated that the introduction of an appropriate amount of Al could not only enhance surface acidity and promote the formation of defective Zr-Ov-Al structures (Ov: oxygen vacancy) but also facilitate the generation of interfacial Niδ+ species bound to the support. Over the Ni-based catalyst bearing an Al2O3:ZrO2 mass ratio of 5:2, a high cyclohexane yield of ～77.4% was attained at 230 °C and 1.0 MPa initial hydrogen pressure. The high catalytic HDO efficiency was revealed to be correlated with the catalytic synergy between Ni0 and adjacent interfacial Niδ+ species, together with the promotion of neighboring defective oxygen vacancies and acidic sites, which contributed to the enhanced activation of the methoxy group in anisole and reaction intermediate and thus greatly improved HDO activity. The present findings offer a new and promising guidance for constructing high-performance metal-based catalysts via a rational surface-interface engineering.
Highly Selective Hydrodeoxygenation of Lignin to Naphthenes over Three-Dimensional Flower-like Ni2P Derived from Hydrotalcite
Chen, Guanyi,Diao, Xinyong,Ji, Na,Jia, Zhichao,Li, Changzhi,Li, Xinxin,Liu, Caixia,Liu, Qingling,Lu, Xuebin,Ma, Longlong,Song, Chunfeng,Wang, Shurong,Zhao, Yujun
, p. 1338 - 1356 (2022/02/07)
A strategy for low-temperature synthesis of hydrotalcite-based nickel phosphide catalysts (Ni2P-Al2O3) with flower-like porous structures was proposed. The in situ reduction of red phosphorus at 500 °C enables Ni2P catalysts with small particle size and abundant active and acidic sites, which facilitate the activation of substrates and H2. In the hydrodeoxygenation of guaiacol, a 100% conversion and 94.5% yield of cyclohexane were obtained over the Ni2P-Al2O3 catalyst under 5 MPa H2 at 250 °C for 3 h. Other lignin-derived phenolic compounds could also afford the corresponding alkanes with yields higher than 85%. Moreover, Ni2P-Al2O3 exhibited high hydrodeoxygenation activity in the deconstruction of more complex wood structures, including lignin oil and real lignin. Among the two different types of Ni sites of Ni(1) and Ni(2) in Ni2P, density functional theory (DFT) calculations showed that the Ni(2) site, highly exposed on the Ni2P-Al2O3 surface, possesses a stronger ability to break C-OH bonds during the hydrodeoxygenation of guaiacol in comparison with the Ni(1) site.
