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

Production of abiotic or biogenic hydrocarbons on rock particles in the presence of H2O and carbon compounds

Abiotic H2 and hydrocarbons are found in fluids discharged from ultramafic-hosted hydrothermal vents. Beneath the hydrothermal vents, abiotic H2 and hydrocarbons can be formed by serpentinization reactions and Fischer-Tropsch-type hydrocarbon-forming reactions, respectively, over ultramafic rocks. However, the source rocks that form abiotic H2 and hydrocarbons may extend to broader subsurface rocks. Here, we show that various rock constituents (solid acids) play a catalytic role in the formation of H and OH radicals via H2O dissociation, as well as in the formation of diverse hydrocarbons via the synthesis reactions of H radicals and inorganic carbons or by H radical-induced dissociation of organic carbons. The mechanisms and characteristics of these formation processes were explored through a series of reactor-based laboratory experiments. Four types of solid acid-containing rocks were mixed with H2O and a carbon source and reacted at different temperatures and pressures for different reaction periods. The product gases were analyzed via GC/MS. Twenty-nine hydrocarbons up to C11, predominantly including CH4 and aromatic hydrocarbons, were identified when CO2 (inorganic carbon source) and basalt particles were used; in contrast, 42 hydrocarbons up to C11, predominantly including CH4 and aliphatic hydrocarbons, were identified when soybean oil (organic carbon source) and basalt particles were used. The results of this study imply that abiotic H2 and diverse hydrocarbons are produced in the subsurface of Earth regardless of the presence of living organisms and suggest that solid acid-containing rocks near hot springs or volcanic areas can promote CO2 conversion into CH4 with the aid of H radicals supplied from H2O dissociation over the rocks.

Synthesis of Nucleic Acid Bases by Metal Ferrite Nanoparticles from a Single Carbon Atom Precursor Molecule: Formamide

The synthesis of prebiotic molecules from simple precursors is believed to be a crucial scheme in order to study the origin of life processes. The present study describes the one-pot synthesis of purine and pyrimidine nucleic acid bases in the presence of pre-biologically significant binary metal oxide nanoparticles, metal ferrites, namely NiFe2O4, CoFe2O4, CuFe2O4, ZnFe2O4 and MnFe2O4. The products identified are cytosine, isocytosine, 4(3H)-pyrimidinone, adenine, hypoxanthine and purine. The ability of isocytosine (a constitutional isomer of cytosine) to recognize cytosine and guanine through normal and reversed Watson-Crick pairing respectively, demonstrates an important storyline for the genesis of ancient nucleic acids. The relevance of other synthesized nucleic acid bases with respect to the origin of life is also discussed. The divalent metal ions in iron oxide make it an appropriate catalytic system because it demonstrates excellent catalytic performance for the nucleic acid bases synthesis with significantly high yield, as compared to pure iron oxide and some other minerals like silica, alumina, manganese oxides and double metal cyanide complexes.

Systems protobiology: origin of life in lipid catalytic networks

Life is that which replicates and evolves, but there is no consensus on how life emerged. We advocate a systems protobiology view, whereby the first replicators were assemblies of spontaneously accreting, heterogeneous and mostly non-canonical amphiphiles. This view is substantiated by rigorous chemical kinetics simulations of the graded autocatalysis replication domain (GARD) model, based on the notion that the replication or reproduction of compositional information predated that of sequence information. GARD reveals the emergence of privileged non-equilibrium assemblies (composomes), which portray catalysis-based homeostatic (concentration-preserving) growth. Such a process, along with occasional assembly fission, embodies cell-like reproduction. GARD pre-RNA evolution is evidenced in the selection of different composomes within a sparse fitness landscape, in response to environmental chemical changes. These observations refute claims that GARD assemblies (or other mutually catalytic networks in the metabolism first scenario) cannot evolve. Composomes represent both a genotype and a selectable phenotype, anteceding present-day biology in which the two are mostly separated. Detailed GARD analyses show attractor-like transitions from random assemblies to self-organized composomes, with negative entropy change, thus establishing composomes as dissipative systems-hallmarks of life. We show a preliminary new version of our model, metabolic GARD (M-GARD), in which lipid covalent modifications are orchestrated by non-enzymatic lipid catalysts, themselves compositionally reproduced. M-GARD fills the gap of the lack of true metabolism in basic GARD, and is rewardingly supported by a published experimental instance of a lipid-based mutually catalytic network. Anticipating near-future far-reaching progress of molecular dynamics, M-GARD is slated to quantitatively depict elaborate protocells, with orchestrated reproduction of both lipid bilayer and lumenal content. Finally, a GARD analysis in a whole-planet context offers the potential for estimating the probability of life's emergence. The invigorated GARD scrutiny presented in this review enhances the validity of autocatalytic sets as a bona fide early evolution scenario and provides essential infrastructure for a paradigm shift towards a systems protobiology view of life's origin.

Surface interaction of ribonucleic acid constituents with spinel ferrite nanoparticles: a prebiotic chemistry experiment

A prebiotic chemistry experiment involving interaction between ribonucleotides and spinel ferrite nanoparticles has been carried out.

A novel approach to reduction of CO2into methanol by water splitting with aluminum over a copper catalyst

A novel method of water splitting for CO₂reduction into methanol was proposed by directly using commercially available and non-precious Al and Cu powder as a reductant and catalyst, respectively.