TiO2-Supported Pd as an Efficient and Stable Catalyst for the Mild Hydrotreatment of Tar-Type Compounds

Abstract

The mild hydrotreatment of a model mixture of tar-type compounds (i.e., naphthalene, 1-methylnaphthalene, acenaphthylene, and phenanthrene) to produce partially hydrogenated products in the range of C9–C15 was studied over Pd supported on TiO2 possessing different crystalline phases. Pd-based catalysts were prepared and characterized by ICP analysis, XRD, N2 adsorption isotherms, HR-TEM, and NH3-TPD, among others. The hydrotreatment activity and selectivity towards the desired hydrogenated products (i.e., tetralin and others) increased with both the acidity and surface area of the catalyst, along with the presence of small and well distributed Pd nanoparticles. For the selected 1.3 wt%Pd/TiO2 nano catalyst, the operational conditions for maximizing tar conversion were found to be 275 °C, 30 bar of H2, and 0.2 g of catalyst for 7 h. The catalyst revealed remarkable hydrotreatment activity and stability after several reuses with practically no changes in TiO2 structure, quite low carbon deposition, and any Pd leaching detected, thus maintaining both a small Pd particle size and adequate distribution, even after regeneration of the catalyst. Additionally, the Pd/TiO2 nano catalyst was demonstrated to be more active than other commonly used metal/alumina and more selective than metal/USY zeolites in the mild hydrotreatment of tar-type compounds, thus providing an efficient catalytic route for obtaining partially hydrogenated C9–C15 hydrocarbons useful as jet-fuel components or additives (improvers), as well as chemicals and solvents for industrial applications.

Stepwise Reduction and In Situ Loading of Core‐Shelled Pt@Cu Nanocrystals on TiO2–NTs for Highly Active Hydrogen Evolution

“…On based of the above findings, it can be speculated that the stepwise formed bimetal nanoagents with small enough size could enter into the pores of TiO 2 -NTs, leading to thickening the tube wall and reducing the inner diameter, which thus results in the disappearance of most micro-pores and the reduction of the pore size of some mesopores. [43,44] 2.5. Catalysis Activity of Pt@Cu(x)/TiO 2…”

Increasing Ni Dispersion on a Carbon-Supported Catalyst for Hydrogenation Saturation of Naphthalene: Effect of Different Alkanol Solvents

“…Naphthalene (NL) is typically used as a model compound to explore the catalytic hydrogenation activity of the catalysts and the mechanisms of the hydrogenation saturation of polyaromatic hydrocarbons . The hydrogenation of NL is a consecutive reaction, which mainly produces tetralin (TL) and decalin (DL) . As the main product of the saturation hydrogenation of NL, DL is primarily used as an essential organic solvent, hydrogen storage medium, raw material for the production of 6,10-nylon, and jet fuel stabilizers .…”

“…2 The hydrogenation of NL is a consecutive reaction, which mainly produces tetralin (TL) and decalin (DL). 3 As the main product of the saturation hydrogenation of NL, DL is primarily used as an essential organic solvent, hydrogen storage medium, raw material for the production of 6,10-nylon, and jet fuel stabilizers. 4 Significantly, the hydrogenation of NL is reversible and difficult to dearomatize the stable aromatic ring from TL.…”