Hydrothermal synthesis of long-chain hydrocarbons up to C24 with NaHCO3-assisted stabilizing cobalt

Abiotic CO2 reduction on transition metal minerals has been proposed to account for the synthesis of organic compounds in alkaline hydrothermal systems, but this reaction lacks experimental support, as only short-chain hydrocarbons (<C5) have been synthesized in artificial simulation. This presents a question: What particular hydrothermal conditions favor long-chain hydrocarbon synthesis? Here, we demonstrate the hydrothermal bicarbonate reduction at ∼300 °C and 30 MPa into long-chain hydrocarbons using iron (Fe) and cobalt (Co) metals as catalysts. We found the Co0 promoter responsible for synthesizing long-chain hydrocarbons to be extraordinarily stable when coupled with Fe−OH formation. Under these hydrothermal conditions, the traditional water-induced deactivation of Co is inhibited by bicarbonate-assisted CoOx reduction, leading to honeycomb-native Co nanosheets generated in situ as a new motif. The Fe−OH formation, confirmed by operando infrared spectroscopy, enhances CO adsorption on Co, thereby favoring further reduction to long-chain hydrocarbons (up to C24). These results not only advance theories for an abiogenic origin for some petroleum accumulations and the hydrothermal hypothesis of the emergence of life but also introduce an approach for synthesizing long-chain hydrocarbons by nonnoble metal catalysts for artificial CO2 utilization.

Asymmetric radical carboesterification of dienes

The straightforward strategy of building a chiral C-O bond directly on a general carbon radical center is challenging and stereocontrol of the reactions of open-chain hydrocarbon radicals remains a largely unsolved problem. Advance in this elementary step will spur the development of asymmetric radical C-O bond construction. Herein, we report a copper-catalyzed regioselective and enantioselective carboesterification of substituted dienes using alkyl diacyl peroxides as the source of both the carbon and oxygen substituents. The participation of external acids in this reaction substantially extends its applicability and leads to structurally diverse allylic ester products. This work represents the advance in the key elementary reaction of intermolecular enantioselective construction of C-O bond on open-chain hydrocarbon radicals and may lead to the discovery of other asymmetric radical reactions.

Improving Thermal Diffusivity of Supported Fe-based Fisher -Tropsch catalyst to enhance long-chain Hydrocarbon production

Hydrocarbon fuels and other high-valued chemicals traditionally obtained from petroleum can be produced via the green and sustainable Fischer-Tropsch synthesis (FTS). However, the FTS reaction is highly exothermic which is...

Understanding deep dehydrogenation and cracking of n-butane on Ni(111) by a DFT study

A DFT study on deep dehydrogenation and cracking of long-chain hydrocarbon involving the cleavage of different C–C bonds on nickel.

Heavy Metal-induced Cuticular Alkane Changes of Tall Fescue (Festuca arundinacea) Plantlets

Heavy metal pollution of ecosystems is of great concern, due to the persistence of metals in ecosystem. In this regard, the mountainous pastures of Romanian Carpathians, especially those in the areas of abandoned mines, need particular attention. The aim of this work was to assess the effect of heavy metals and metalloids exposure on cuticular wax composition of tall fescue leaves (Festuca arundinacea). Therefore, we have particularly investigated the variations of long chain hydrocarbon fractions, which are acknowledged to act as a protection for plants especially in toxic environments. The exposure experiments were conducted in triplicates for arsenic and the following metal ions: Ba2+, Cu2+, Fe2+ and Pb2+. The 0.5 mM aqueous solutions of their corresponding salts were used as treatment solutions. Triplicate experiments were also performed for control samples using distilled water as exposure media. The plantlets were kept for growing in controlled environment for 15 days followed by n-hexane hydrocarbon fraction extraction from 0.5 g of sampled leaves. The obtained extracts were semi-quantitatively analyzed (identification followed by peak area measurement) through an optimized method based on gas-chromatography coupled with mass spectrometry. We focused on the measurement of several long chain n-alkanes with the following number of carbon atoms: C21-C31. Significant differences were obtained between results performed for Ba2+, Pb2+ and Fe2+, when compared to AsO43- and Cu2+, which may suggest multiple mechanisms through which the tested plants could develop and adapt when exposed to various chemicals characterized by different degrees of toxicity.