TY - JOUR
T1 - Deoxygenation of oleic acid
T2 - Influence of the synthesis route of Pd/mesoporous carbon nanocatalysts onto their activity and selectivity
AU - Dragu, A.
AU - Kinayyigit, S.
AU - García-Suárez, E. J.
AU - Florea, M.
AU - Stepan, E.
AU - Velea, S.
AU - Tanase, L.
AU - Collière, V.
AU - Philippot, K.
AU - Granger, P.
AU - Parvulescu, V. I.
N1 - Publisher Copyright:
© 2015 Elsevier B.V. All rights reserved.
PY - 2015/9/5
Y1 - 2015/9/5
N2 - Supported Pd nanocatalysts were prepared by deposition of Pd nanoparticles (NPs) onto spherical mesoporous carbon beads (MB) functionalized by thermal or acidic treatement. The Pd NPs were synthesized by decomposition of [Pd2(dba)3] (dba: dibenzylideneacetone) under dihydrogen either directly on the carbon supports without stabilizer leading to naked Pd NPs (Pd/MB series) or in solution in the presence of a stabilizer (polymer (PVP series) or triphenylphosphine (TPP series)) to obtain stable colloidal solutions that were further used to impregnate the carbon materials to have carbon-deposited Pd NPs. The NPs deposited on carbon displayed a Pd loading from 0.5 to 14.8 wt.% and were characterized by different techniques (nitrogen physisorption at 77 K, H2-chemissorption and TPD, XRD, XPS and HRTEM). Their catalytic performance in deoxygenation of oleic acid was evaluated in batch and flow reaction conditions. Flow conditions led to superior results compared to batch. No aromatic compounds were detected as side products, but in the case of the Pd/MB series, octadecanol and octadecane were significantly formed suggesting the involvement of a deoxygenation mechanism in which the hydrocarbons were produced via both decarbonylation/decarboxylation and dehydration steps. Further experiments carried out in H2/N2 mixture or in pure N2 highlighted the key role of hydrogen. For a N2/H2 of 2.5:1 the dehydration route was crossing out and even no traces of octadecanol nor octadecane were detected. Then, complete removal of H2 produced heptadecene in a high excess compared to heptadecane (almost 7-1) thus suggesting the decarbonylation/decarboxylation steps as the main route. ICP-OES measurements indicated no leaching of palladium and simple washing of catalysts with mesitylene allowed recycling without any change in conversion or product distribution.
AB - Supported Pd nanocatalysts were prepared by deposition of Pd nanoparticles (NPs) onto spherical mesoporous carbon beads (MB) functionalized by thermal or acidic treatement. The Pd NPs were synthesized by decomposition of [Pd2(dba)3] (dba: dibenzylideneacetone) under dihydrogen either directly on the carbon supports without stabilizer leading to naked Pd NPs (Pd/MB series) or in solution in the presence of a stabilizer (polymer (PVP series) or triphenylphosphine (TPP series)) to obtain stable colloidal solutions that were further used to impregnate the carbon materials to have carbon-deposited Pd NPs. The NPs deposited on carbon displayed a Pd loading from 0.5 to 14.8 wt.% and were characterized by different techniques (nitrogen physisorption at 77 K, H2-chemissorption and TPD, XRD, XPS and HRTEM). Their catalytic performance in deoxygenation of oleic acid was evaluated in batch and flow reaction conditions. Flow conditions led to superior results compared to batch. No aromatic compounds were detected as side products, but in the case of the Pd/MB series, octadecanol and octadecane were significantly formed suggesting the involvement of a deoxygenation mechanism in which the hydrocarbons were produced via both decarbonylation/decarboxylation and dehydration steps. Further experiments carried out in H2/N2 mixture or in pure N2 highlighted the key role of hydrogen. For a N2/H2 of 2.5:1 the dehydration route was crossing out and even no traces of octadecanol nor octadecane were detected. Then, complete removal of H2 produced heptadecene in a high excess compared to heptadecane (almost 7-1) thus suggesting the decarbonylation/decarboxylation steps as the main route. ICP-OES measurements indicated no leaching of palladium and simple washing of catalysts with mesitylene allowed recycling without any change in conversion or product distribution.
KW - Catalysis
KW - Deoxygenation reaction
KW - Mesoporous carbon
KW - Oleic acid
KW - Palladium
KW - Supported nanoparticle
UR - https://www.scopus.com/pages/publications/84942366449
U2 - 10.1016/j.apcata.2015.01.008
DO - 10.1016/j.apcata.2015.01.008
M3 - Article
AN - SCOPUS:84942366449
SN - 0926-860X
VL - 504
SP - 81
EP - 91
JO - Applied Catalysis A: General
JF - Applied Catalysis A: General
ER -