The abiotic formation of hydrocarbons from dissolved CO2 under hydrothermal conditions with cobalt-bearing magnetite.

Conversion of CO(2) to organic compounds in hydrothermal systems is important in understanding prebiotic chemical evolution leading to the origin of life. However, organic compounds with carbon number of more than 3 have never been produced from dissolved CO(2) in simulated hydrothermal experiments. In this paper, we report that not only CH(4), C(2)H(6) and C(3)H(8), but also n-C(4)H(10) and n-C(5)H(12) could be produced from dissolved CO(2) and H(2) in the presence of cobalt-bearing magnetite at 300 degrees C and 30 MPa. It is shown that unbranched alkanes in Anderson-Schulz-Flory distribution were the dominant hydrocarbon products produced from dissolved CO(2) catalyzed by cobalt-bearing magnetite under certain hydrothermal conditions. It is proposed that magnetite with other transition metals may act potentially as effective mineral catalysts for abiotic formation of organic compounds from dissolved CO(2) in hydrothermal systems.