Recently, Associate Professor Daoping He from the State Key Laboratory of Green Papermaking and Resource Recycling and the China-UK Low Carbon College published a research paper titled “Metallic molybdenum sulfide catalyses protometabolic carbon dioxide reaction networks under extreme conditions” in Nature Communications. By simulating extreme deep-Earth environments, the study successfully constructed a prebiotic metabolic reaction network using carbon dioxide as the carbon source, achieving the self-organized evolution from inorganic compounds to complex organic metabolic systems. The first author of the paper is Ph.D. candidate Pengfei Chen (formerly a master’s student at the China-UK Low Carbon College), with corresponding authors including Associate Professor Daoping He from the China-UK Low Carbon College, Associate Researcher Yang Yang from the School of Environmental Science and Engineering, and Professor Fangming Jin. Shanghai Jiao Tong University is the primary affiliation of the paper.

Deep hydrothermal systems provide a unique prebiotic chemical environment for the abiotic reduction of CO₂, emerging as a new research hotspot in CO₂ resource utilization. Deep-sea and subsurface exploration has revealed the existence of a self-sustaining biosphere in Earth's depths, independent of solar radiation and primarily driven by alkaline hydrothermal systems. These systems feature extreme chemical conditions such as high temperature, high pressure, and hydrogen-rich environments, offering an ideal reaction medium for non-photosynthetic CO₂ fixation. Alkaline hydrothermal carbon fixation not only accounts for the abiotic origin of certain hydrocarbon resources but is also considered a potential chemoautotrophic environment preceding the origin of life. However, current understanding of CO₂ transformation in deep hydrothermal systems remains at a preliminary stage. Most existing studies focus on single reaction pathways or the performance of specific catalysts, lacking systematic exploration of multi-pathway, multi-component, and dynamically coupled carbon reaction networks. Particularly under simulated prebiotic conditions, key scientific challenges persist: how to achieve the directional synthesis of complex organic molecules through non-enzymatic catalysis and how to construct self-organizing, autocatalytic carbon metabolic networks. Addressing these questions holds profound implications for understanding the diversity and stability of biogeochemical cycles, as well as the evolutionary dynamics of global climate change.

Figure 1. Schematic diagram of the CO₂ reduction reaction network catalyzed by metallic-phase molybdenum sulfide.

Based on the coordination structure and catalytic mechanism of the Mo-S₂-pterin distorted active site in carbon-fixing enzymes, a metallic-phase molybdenum sulfide mineral with a similar distorted configuration was successfully synthesized. Under conditions simulating natural hydrothermal environments, this mineral can directly catalyze the reduction of CO₂ to produce 32 metabolic intermediates and end products, including five key universal metabolic precursors: acetate, pyruvate, oxaloacetate, succinate, and α-ketoglutarate. The reaction system encompasses 7 out of 11 products from the reductive tricarboxylic acid (rTCA) cycle, 9 out of 13 products from the 3-hydroxypropionate-4-hydroxybutyrate (3HP-4HB) pathway, 9 out of 11 products from the dicarboxylate-4-hydroxybutyrate (DC-4HB) pathway, 6 out of 9 intermediates from the glyoxylate cycle, and all intermediates from the complete acetyl-CoA and ethylmalonyl-CoA (EMCP) pathways. The multicarboxylic acid products exhibit periodic oscillatory distribution patterns over time, demonstrating dynamic behavior akin to autocatalytic networks in natural carbon cycles. The diversity of products, the comprehensiveness of pathway coverage, and their high functional relevance significantly surpass previous achievements in constructing carbon cycle reaction networks through non-enzymatic or artificial catalytic systems.  

In situ spectroscopic analysis and theoretical calculations reveal that metallic-phase molybdenum sulfide with sulfur vacancies effectively suppresses the formate pathway of CH_x precursor CO (CO + OH⁻ → HCOO⁻), instead promoting its conversion into reactive radicals (CO_ads → CH_x• → CH_xCO•) while significantly enhancing its adsorption capacity and coupling reactivity in aqueous solutions. This regulatory mechanism markedly improves CO₂ conversion efficiency, achieving a CO₂ conversion rate of up to 68.6% and a C₂₊ product selectivity of 74.5%, outperforming previously reported CO₂/NaHCO₃ thermocatalytic systems.

Figure 2. Reaction network model of transition metal sulfide-catalyzed carbon dioxide reduction in hydrothermal vent systems.

This study successfully constructed a multidimensional dynamic carbon metabolism network in a non-enzymatic system. It not only provides a crucial theoretical foundation for achieving the “dual carbon” goals, advancing future energy technologies, promoting progress in synthetic biology, and expanding organic synthesis strategies in extreme environments such as the deep sea and space, but also offers key insights into the geochemical mechanisms underlying the formation of metabolic systems during the origin of life.

Link to the original paper：https://doi.org/10.1038/s41467-026-69255-w