We investigate the stability and dissociation of methane, which is the most abundant organic molecule in the universe, using diamond anvil cell （DAC） with in situ Raman spectroscopy up to 903K and 21 GPa. At the tem...We investigate the stability and dissociation of methane, which is the most abundant organic molecule in the universe, using diamond anvil cell （DAC） with in situ Raman spectroscopy up to 903K and 21 GPa. At the temperatures of 793 and 723 K and the corresponding pressures of 16.15 and 20.30 GPa, methane dissociates to form carbon ＇soot＇ and heavier hydrocarbons involving C=C and C≡C bonds. However, if the pressure is not very high, methane remains stability up to the highest temperature of 903 K of the work. The four symmetric C-H bonds of methane split at high temperatures and at high pressures, and there is at least one phase transition of crystalline symmetry from face centred cubic （fcc） to hexagonal close packed （hcp） before dissociation.展开更多
Under high pressures of several giga-pascals using hydrothermal diamond anvil cell,methane generated directly from CaCO3 reduction in gold-lined chamber is in situ measured by Raman spectroscopy at the temperature of ...Under high pressures of several giga-pascals using hydrothermal diamond anvil cell,methane generated directly from CaCO3 reduction in gold-lined chamber is in situ measured by Raman spectroscopy at the temperature of 550℃ Fhe reducing agents include FeO,SiO and natural fayalite（Fe2SiO4）,and the resource of hydrogen are water and natural serpentine（Mg3Si2O5（OH）4）. The study demonstrates the existence of abiogenic formation of methane under high pressures in the Earth＇s interior and that the application of high pressure to catalyze multicomponent reactions is a very promising method.展开更多
基金Supported by National Natural Science Foundation of China under Grant No. 20777048, and the Shanghai Leading Academic Disciplines （T105）.
文摘We investigate the stability and dissociation of methane, which is the most abundant organic molecule in the universe, using diamond anvil cell （DAC） with in situ Raman spectroscopy up to 903K and 21 GPa. At the temperatures of 793 and 723 K and the corresponding pressures of 16.15 and 20.30 GPa, methane dissociates to form carbon ＇soot＇ and heavier hydrocarbons involving C=C and C≡C bonds. However, if the pressure is not very high, methane remains stability up to the highest temperature of 903 K of the work. The four symmetric C-H bonds of methane split at high temperatures and at high pressures, and there is at least one phase transition of crystalline symmetry from face centred cubic （fcc） to hexagonal close packed （hcp） before dissociation.
文摘Under high pressures of several giga-pascals using hydrothermal diamond anvil cell,methane generated directly from CaCO3 reduction in gold-lined chamber is in situ measured by Raman spectroscopy at the temperature of 550℃ Fhe reducing agents include FeO,SiO and natural fayalite（Fe2SiO4）,and the resource of hydrogen are water and natural serpentine（Mg3Si2O5（OH）4）. The study demonstrates the existence of abiogenic formation of methane under high pressures in the Earth＇s interior and that the application of high pressure to catalyze multicomponent reactions is a very promising method.
