Reaction between H2, CO, and H2S over Fe, Ni metal in the solar nebula: Experimental evidence for the formation of sulfur‐bearing organic molecules and sulfides

Abstract— Detailed laboratory studies have been carried out in order to simulate the interaction between nanometer‐sized kamacite metal particles and different gas mixtures consisting of H 2 :H 2 S (250:0.1), H 2 :CO (250:1), and H 2 :CO:H 2 S (250:1:0.1) under nebular‐type conditions (5 × 10 −4 atm and 473 K). Reaction of H 2 + H 2 S with kamacite particles for 1000 h leads to the formation of pyrrhotite. Incorporation of CO into the gaseous reactant mixture results in the formation of both sulfide and carbide phases. At the same time, amorphous C is deposited onto the metal particles and organic molecules are evolved, namely hydrocarbons and thiols in the C 1 ‐C 5 and C 1 ‐C 2 range, respectively. Carbon deposition and production of organics are enhanced with respect to experiments performed with H 2 + CO, where a carbide phase is formed. There is no evidence for the existence of S‐poisoning effects on the metal‐catalysed hydrogenation of CO through Fischer‐Tropsch‐type reactions in nebular environments. In fact, it is experimentally demonstrated that S‐containing organic species could be synthesized by such reactions from nebular gas.