The Chemical Reaction Of Ammonium Bicarbonate Under High Temperature And High Pressure And Its Potential Significance To The Origin Of Life

Chemieal evolution theory postulates that the first step in the origin of life is that:small inorganic molecules could transform to small organic molecules in the early Earth enviromnent,which then could provide substances that are essential for the formation of life-sustaining biomolecules(amino acid and protein).These life-sustaining substances might have been synthesized spontaneously by chemical reactions of inorganic compounds in deep-sea hydrothermal fluids at high temperature and under high pressure(HTHP).Therefore,high pressure might have played an important role at the first step in origin of life.Our recent research results show that some multi-carbon hydrocarbon organic molecules can be synthesized from single inorganic small molecules at relatively HTHP,providing the basis for the formation of life-essential organic molecules.In our experiments,we have chosen inorganic NH4HCO3 that contains the four life-essential elements C,H,0 and N as the starting material for the in-situ measurements of its chemical reactions at HTHP using infrared absorption spectroscopy(IR),with a preset initial pressure of 2 or 4 GPa.The experimental results showed that there were large and irreversible changes in the IR spectra after the tenperature reached~150?,and that the IR spectra changed again after the system was cooled down to room temperature and decompressed to the atmospheric pressure.Combing these results with the data from the GC-MS measurements of the chemical reaction products,we identified the products formed at~150? as mixtures of unsaturated organic coiqpounds,which changed again to saturated hydrocarbons(liquid paraffin)after quenching to ambient terperature and pressure.This HTHP reaction process may simulate the conversion of inorganic molecules to organic molecules in the deep-sea hydrothermal environment of the early Earth,suggesting that the fornation of alkane(CxHy)organic matter might be the necessary initial stage of life formation.