Fine-tuning the catalytic activity by applying nitrogen-doped carbon nanotubes as catalyst supports for the hydrogenation of olefins

Abstract

Nitrogen-free multi-wall carbon nanotubes (MWCNTs) and N-doped bamboo-like carbon nanotubes (BCNTs) were synthesized by using catalytic vapor deposition (CVD) and used as catalyst support materials. Pd, Rh, Ru, and Ir have been deposited onto the nanotubes to achieve metal/nanotube catalysts. The catalytic activity of the samples was fine-tuned by changing the type of support. BCNT supported Pd and Rh (Pd/BCNT, Rh/MWCNT) catalysts were found to be the most active for liquid phase hydrogenation of octadecene amongst these samples. The initial olefin hydrogenation rate of the Pd/BCNT sample was slightly higher than the corresponding MWCNT-supported catalyst. Based on the hydrogenation reaction, the performance of these catalyst had been ranked as follows: Pd/BCNT ≈ Rh/MWCNT > Pd/ MWCNT > Rh/BCNT > > Ir/MWCNT > Ru/BCNT > Ir/BCNT > Ru/MWCNT. The structural properties of chemisorbed Pd on MWCNT and N-BCNT were also characterized by means of computational chemical methods in order to shed some light on the nature of metal binding properties of N-doped and undoped surfaces. The calculations shown preference towards the edges of the surfaces which is in good agreement with the experimental findings.

Current approaches, emerging developments and functional prospects for lignin-based catalysts – a review

“…17,154 Carbon-based catalysts were used in various catalytic reactions, including hydrogenation, esterification, hydrolysis, and condensation, to name a few. 152,153,155 Suriyachai et al used a heterogeneous H 3 PO 4 -activated carbon for the hydrolysis of lignocellulose polysaccharides into valuable biofuels and chemicals. 156 The catalyst showed 84.6% recovery of pentoses, and a 58.3% yield of hexose, with >80% activity after reuse in 5 successive batch runs.…”

“…152,154,226,227 Multi-walled carbon nanotubes (MWCNTs) and nitrogen-doped bamboo-like carbon nanotubes (BCNTs) comprising Pd, Rh, Ru and Ir catalysts were used in the catalytic hydrogenation of 1-octadecene to octadecane, and the conversion reached 96.5%. 155 Mesoporous carbon microspheres loaded with Ru NPs were used as heterogeneous catalysts for the hydrogenation of aromatic compounds. 152 The conversion and selectivity of phenol hydrogenation into cyclohexanol reached 100%, given the hierarchically porous character of the catalyst that promotes effective mass transfer of the reactants.…”

Fe-CONTAINING CARBON NANOTUBES AS CATALYSTS IN THE AEROBIC OXIDATION REACTIONS OF DECALIN AND TETRADECANE

“…In [18] the study developed catalysts containing 5% by weight of metal (Pd, Rh, Ru, and Ir) and used nitrogen-free multi-walled carbon nanotubes (MWCNTs) and N-containing carbon nanotubes (N-MWCNTs) as supporting materials. The prepared catalytic samples were used in the hydrogenation reaction of 1-octadecene and the catalytic activities were compared.…”

“…The selective hydrogenation of nitrobenzophenone to aminobenzophene by a catalyst sample (Pd/N-CNTs) obtained by modifying nitrogen and the same metal nanoparticles in modern CNTs was investigated, as a result, Pd/N-CNTs were more selective than Pd/CNTs and the added carbon supplement Pd was aminobenzophenone [24]. In addition, Pd/N-CNTs are promising catalysts for selective reductions of cinnamaldehyde [25,18].…”

How to Make a Cocktail of Palladium Catalysts with Cola and Alcohol: Heteroatom Doping vs. Nanoscale Morphology of Carbon Supports

“…This is especially pronounced for palladium catalysts on various carbon materials, which are widely used in cross-coupling reactions. In recent years, studies of doped carbon materials as catalyst supports and their influence on the operation of metal catalysts have been of particular interest [4][5][6][7][8][9][10].…”