TY - JOUR

T1 - Oligomerization and carbonization of polycyclic aromatic hydrocarbons at high pressure and temperature

AU - Chanyshev, Artem D.

AU - Litasov, Konstantin D.

AU - Shatskiy, Anton F.

AU - Furukawa, Yoshihiro

AU - Yoshino, Takashi

AU - Ohtani, Eiji

PY - 2015

Y1 - 2015

N2 - We have examined the stabilities of different polycyclic aromatic hydrocarbons (PAHs) at 7 GPa and 773-973 K and at 16 GPa and 300 K. Experiments were performed using a largevolume multi-anvil apparatus. Quenched products were analyzed by matrix-assisted laser desorption/ionization (MALDI) and Raman spectroscopy. The MALDI measurements revealed the considerable oligomerization of PAHs at 7 GPa and 773-873 K and insignificant PAH oligomerization at 16 GPa and 300 K. At 7 GPa and 773 K, oligomers with molecular weight up to 3400 Da were found, while only a small number of dimers of the starting PAHs were detected at 16 GPa and 300 K. PAH decomposition at 7 GPa occurred from 873 to 973 K, and the decomposition products consisted of nanocrystalline graphite. The determined decomposition temperatures of the PAHs (873-973 K) are much lower than Earth's geotherms and the subduction slab P-T profiles at 7 GPa; therefore, PAH inclusions in mantle-derived minerals, which can be crystallized at 6-7 GPa and 1600-1700 K, should be secondary phases and could be formed by the successive polycondensation of simple hydrocarbon molecules under natural catalysts during eruption processes at sub-ambient pressures and temperatures.

AB - We have examined the stabilities of different polycyclic aromatic hydrocarbons (PAHs) at 7 GPa and 773-973 K and at 16 GPa and 300 K. Experiments were performed using a largevolume multi-anvil apparatus. Quenched products were analyzed by matrix-assisted laser desorption/ionization (MALDI) and Raman spectroscopy. The MALDI measurements revealed the considerable oligomerization of PAHs at 7 GPa and 773-873 K and insignificant PAH oligomerization at 16 GPa and 300 K. At 7 GPa and 773 K, oligomers with molecular weight up to 3400 Da were found, while only a small number of dimers of the starting PAHs were detected at 16 GPa and 300 K. PAH decomposition at 7 GPa occurred from 873 to 973 K, and the decomposition products consisted of nanocrystalline graphite. The determined decomposition temperatures of the PAHs (873-973 K) are much lower than Earth's geotherms and the subduction slab P-T profiles at 7 GPa; therefore, PAH inclusions in mantle-derived minerals, which can be crystallized at 6-7 GPa and 1600-1700 K, should be secondary phases and could be formed by the successive polycondensation of simple hydrocarbon molecules under natural catalysts during eruption processes at sub-ambient pressures and temperatures.

UR - http://www.scopus.com/inward/record.url?scp=84922219376&partnerID=8YFLogxK

U2 - 10.1016/j.carbon.2014.12.011

DO - 10.1016/j.carbon.2014.12.011

M3 - Article

AN - SCOPUS:84922219376

VL - 84

SP - 225

EP - 235

JO - Carbon

JF - Carbon

SN - 0008-6223

IS - 1

ER -