TY - JOUR
T1 - Deoxygenation of oleic acid: Influence of the synthesis route of Pd/mesoporous carbon nanocatalysts onto their activity and selectivity
AU - Dragu, A.
AU - Kinayyigit, S.
AU - Garcia-Suarez, Eduardo J.
AU - Florea, M.
AU - Stepan, E.
AU - Velea, S.
AU - Tanase, L.
AU - Collière, Vincent
AU - Philippot, Karine
AU - Granger, P.
AU - Parvulescu, V.I.
PY - 2015
Y1 - 2015
N2 - Supported Pd nanocatalysts were prepared by deposition of Pd nanoparticles (NPs) onto spherical meso-porous carbon beads (MB) functionalized by thermal or acidic treatement. The Pd NPs were synthesizedby decomposition of [Pd2(dba)3] (dba: dibenzylideneacetone) under dihydrogen either directly on thecarbon supports without stabilizer leading to naked Pd NPs (Pd/MB series) or in solution in the presenceof a stabilizer (polymer (PVP series) or triphenylphosphine (TPP series)) to obtain stable colloidal solu-tions that were further used to impregnate the carbon materials to have carbon-deposited Pd NPs. TheNPs deposited on carbon displayed a Pd loading from 0.5 to 14.8 wt.% and were characterized by differ-ent techniques (nitrogen physisorption at 77 K, H2-chemissorption and TPD, XRD, XPS and HRTEM). Theircatalytic 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 sideproducts, but in the case of the Pd/MB series, octadecanol and octadecane were significantly formed sug-gesting the involvement of a deoxygenation mechanism in which the hydrocarbons were produced viaboth decarbonylation/decarboxylation and dehydration steps. Further experiments carried out in H2/N2mixture or in pure N2highlighted the key role of hydrogen. For a N2/H2of 2.5:1 the dehydration route wascrossing out and even no traces of octadecanol nor octadecane were detected. Then, complete removalof H2produced heptadecene in a high excess compared to heptadecane (almost 7–1) thus suggesting thedecarbonylation/decarboxylation steps as the main route. ICP-OES measurements indicated no leachingof palladium and simple washing of catalysts with mesitylene allowed recycling without any change inconversion or product distribution.
AB - Supported Pd nanocatalysts were prepared by deposition of Pd nanoparticles (NPs) onto spherical meso-porous carbon beads (MB) functionalized by thermal or acidic treatement. The Pd NPs were synthesizedby decomposition of [Pd2(dba)3] (dba: dibenzylideneacetone) under dihydrogen either directly on thecarbon supports without stabilizer leading to naked Pd NPs (Pd/MB series) or in solution in the presenceof a stabilizer (polymer (PVP series) or triphenylphosphine (TPP series)) to obtain stable colloidal solu-tions that were further used to impregnate the carbon materials to have carbon-deposited Pd NPs. TheNPs deposited on carbon displayed a Pd loading from 0.5 to 14.8 wt.% and were characterized by differ-ent techniques (nitrogen physisorption at 77 K, H2-chemissorption and TPD, XRD, XPS and HRTEM). Theircatalytic 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 sideproducts, but in the case of the Pd/MB series, octadecanol and octadecane were significantly formed sug-gesting the involvement of a deoxygenation mechanism in which the hydrocarbons were produced viaboth decarbonylation/decarboxylation and dehydration steps. Further experiments carried out in H2/N2mixture or in pure N2highlighted the key role of hydrogen. For a N2/H2of 2.5:1 the dehydration route wascrossing out and even no traces of octadecanol nor octadecane were detected. Then, complete removalof H2produced heptadecene in a high excess compared to heptadecane (almost 7–1) thus suggesting thedecarbonylation/decarboxylation steps as the main route. ICP-OES measurements indicated no leachingof palladium and simple washing of catalysts with mesitylene allowed recycling without any change inconversion or product distribution.
U2 - 10.1016/j.apcata.2015.01.008
DO - 10.1016/j.apcata.2015.01.008
M3 - Journal article
SN - 0926-860X
JO - Applied Catalysis A: General
JF - Applied Catalysis A: General
ER -