Clay Minerals and Catalysis

More than half a century ago, Irish physicist John Desmond Bernal and Swiss geochemist Victor M. Goldschmidt independently proposed that clay minerals may have played an important role in prebiotic synthesis (Bernal 1949; Goldschmidt 1952). I concur that mineral catalysis must have had a central role in prebiotic synthesis because most uncatalyzed reactions start from simple precursors like hydrogen cyanide (HCN), formaldehyde (HCHO), carbon monoxide (CO), hydrogen sulfide (H2S), possibly ammonia (NH3), and other simple organics. These small molecules lack the three-dimensional conformations that can restrict reaction pathways of surface-bound molecules. Consequently, an indiscriminate array of reaction products is synthesized, as was found in the classic MillerUrey experiment, where diverse groups of organic compounds formed. In that experiment, the smallest molecules, such as the simple amino acid glycine, were produced in the greatest amounts (Miller 1957). Similarly, the Murchison meteorite contains seventeen classes of organics compounds that seem to have been formed by random processes (Cronin 1998).