Methane, abiogenic formation

Horita and Berndt (1999) studied the abiogenic formation of methane under conditions present at hydrothermal vents. Solutions of bicarbonate (HCO3 ) were subjected to temperatures of 470-670 K and a pressure of 40 MPa. Under these conditions, CO2 was reduced only very slowly to methane. Addition of a nickel-iron alloy, which corresponds closely to the minerals in the Earth s crust, led to a clear increase in the reaction rate of methane synthesis. The following reaction is assumed to occur ... 

Horita J, Bemdt ME (1999) Abiogenic methane formation and isotope fractionation under hydrothermal conditions. Science 285 1055-1057... 

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