The Reactivity and Deactivation Mechanism of Ru@C Catalyst over Hydrogenation of Aromatics to Cyclohexane Derivatives

Abstract

Nano Ru supported on carbon catalysts with different Ru nanoparticle sizes were reported for the aromatics (dioctyl phthalate, xylene, p-phenylenediamine, cinnamic acid and nitrobenzene) hydrogenation to the corresponding valueadded cyclohexane derivatives. Ru@C-DP prepared by facile deposition-precipitation strategy, exhibited the smaller Ru nanoparticle (NP) size 2.0 nm, higher Ru dispersion degree (60.2%) and larger Ru specific surface area (220.1 m 2 ⋅g Ru À 1 ) than Ru@C-EG and Ru@C-IM synthesized with ethylene glycol reduction and impregnation method, respectively. Ru@C-DP possessed excellent activity with aromatic conversion � 99% and cyclohexane derivative selectivity � 99%, which was attributed to its smaller Ru NP size, suggesting the presence of a size-dependent effect. Moreover, compared with the commercial Ru@C-ID catalyst, Ru@C-DP showed remarkable reusability in aromatic hydrogenation. After the several hydrogenation recycles, the catalyst lost some activity mainly account for the pore blocking by reactant/product molecules, part oxidation and aggregation of Ru NPs.

NiCo and NiCo Decorated with Ru Nanoparticles for Magnetically Induced Hydroprocessing of Lignin Models

“…Smaller Ru particles exhibit more significant activity in the C–O cleavage, which has been attributed to the higher number of edges and steps in smaller particles, which, in turn, lowers the barriers to the cleavage of both C aromatic –O and C aliphatic –O bonds . On the other hand, Ru nanoparticles smaller than 4.0 nm exhibit higher activity in the hydrogenation of aromatic rings than larger nanoparticles . In specific cases, even isolated Ru atoms have been found to be highly active in the hydrogenation of aromatic rings .…”

“…64 On the other hand, Ru nanoparticles smaller than 4.0 nm exhibit higher activity in the hydrogenation of aromatic rings than larger nanoparticles. 65 In specific cases, even isolated Ru atoms have been found to be highly active in the hydrogenation of aromatic rings. 66 Our ongoing and future work is centered on enhancing the control of Ru speciation within the catalyst to address this complexity and better understand how different Ru species contribute to overall catalytic behavior, enabling us to refine the design of the catalyst to achieve improved performance.…”

Exploration of ZnO Doped Nitrogen-Carbon Derived from Polyamide-Imide for Propane Dehydrogenation

“…Apparently, no characteristic Raman bands of ZnO between 200 cm -1 and 600 cm -1 are observed on the catalysts [30]. However, all the catalysts exhibit the featured D-band and G-band at 1345 cm -1 and 1590 cm -1 , which are attributed to the structural defect of carbon atomic lattice and stretching vibration of carbon atom sp 2 hybridization in plane [31,32]. The ID/IG value for Raman spectra is usually utilized to evaluate the graphitization of the carbon-based materials, as listed in Figure 3.…”

“…The vibration of O-H at the wavenumber of 3432 cm -1 is observed, indicating the presence of H2O molecules on the catalyst surface [33]. The stretching vibrations located at about 2810-3010 cm -1 correspond to C-H bond [31]. The peaks at 1580 cm -1 and 1280 cm -1 can be attributed to C=N bond and N-H bond [34], indicating that N-containing species is successfully retained in the catalyst.…”

Ru@C as a safety mask of RuO4@C for selective catalytic oxidation of alkynyl sulfurs to prepare alkynylsulfones

“…Ru@C could be regarded as a safe mask for RuO 4 @C, and Ru@C was safe and easy to operate compared with the direct use of highly toxic RuO 4 . In addition, Ru@C is a commercialized carbon‐based heterogeneous catalyst for catalytic hydrogenation, 41 which is inexpensive, readily available, and easy to separate from the reaction system by filtration for recycling and reusing. So it is a very efficient catalyst for the synthesis of sulfones and alkynylsulfones.…”