CAREER: Comprehensive Chemical and Isotopic Characterization of Abiotic Organic Synthesis: An Experimental Study and Its Implication for Organic Formation in Hydrothermal Systems

在大多数情况下，在地球表面发现的天然有机化合物被认为是由涉及生物的过程产生的。然而，有一些过程创造有机分子，不需要任何生命或任何生命或以前生命的活动。它们被称为非生物（即，不是生物学的）过程。其中之一是将无机一氧化碳和氢气转化为液态烃的费托工艺。据怀疑，这一过程在地球系统中很重要，如海底热液喷口，在那里，循环进入海洋地壳深处的海水受到岩浆体的加热，并在相对较高的温度下与周围岩石发生反应，改变岩石，产生碳氢化合物，而不受生物或其有机产品的影响。 该教师早期职业发展项目在休斯顿大学建立了一个综合研究和教育计划，致力于提高我们对海底热液系统中非生物有机合成过程的理解，该系统已被提议为生物有机合成和地球生命起源的可能场所。将在实验室中，在类似于天然海底热液环境的条件下，研究由此产生的有机物形成过程的反应机制和控制因素。 研究将包括实验室实验、化学和同位素定性的先进分析技术以及将实验结果与海底热液喷口的样品进行比较。这项工作的更广泛的影响包括教育和研究活动的紧密结合，旨在改善本科生和研究生教育，重点是吸引来自少数群体的学生，在科学中代表性不足，在研究计划。它还将涉及与休斯顿当地学区的广泛互动，以接触初中和高中学生，让他们了解如何对生命起源和碳氢化合物生成进行尖端地球化学研究的第一手知识。这将通过K-12实验室设施的图尔斯之旅和与研究人员及其学生讨论如何进行这些类型的实验以及如何分析和解释所得数据来完成。 这一推广活动的目标是提高学生对科学的认识，以及如何做到这一点，并激励他们在地球科学领域建立职业生涯。其他影响包括通过开发新的分析技术和反应堆设计来建设科学基础设施。这项工作的其他影响包括支持一名早期职业教师，并有可能跨领域提供信息，并在化学和石油工程领域找到应用。这项研究对于了解海底热液系统中非生物生成的有机分子的形成至关重要。它将研究与非生物生成碳氢化合物有关的费托反应。将开展一个实验室实验方案，使用新型反应器和最先进的分析方法，研究在高温和类似于大洋中脊热液系统的条件下流体矿物催化的有机合成。实验装药将包括类似于海底环境中的天然矿物;实验将侧重于确定有机合成过程中发生的反应机制。在该项目期间，将研究非生物产生的有机化合物的反应机制，并确定在最先进的反应器系统中在各种物理化学条件下产生的液体、气体和矿物表面吸附物质中的分子种类的系统识别。分析工作将包括使用气相色谱-质谱法、热解气相色谱-质谱法、纳米二次离子质谱法和液相色谱-质谱法。此外，还将测量新生成的有机化合物的碳和氢同位素特征，并将使用聚集同位素方法分析非生物生成的甲烷的同位素特征，以试图确定除温度外影响地层的控制因素是否起作用。特别是，长链烃、同系烷烃、醇和羧酸等化合物将成为目标，因为每种化合物都与不同的反应机制有关。实验室实验的结果将与在大洋中脊热液喷口进行海洋学考察时收集的特定喷口流体样本的组成和形成的物理化学条件进行比较。

For the most part, naturally occurring organic compounds found on the surface of the Earth are thought to result from processes that involve living things. There are, however, processes that create organic molecules that do not require life or the activity of any living or previously living thing. These are called abiotic (i.e., not biological) processes. One of these is the Fischer-Tropsch process which converts inorganic carbon monoxide and hydrogen into liquid hydrocarbons. It is suspected that this process is important in earth systems, like seafloor hydrothermal vents, where seawater circulating deep into the ocean crust gets heated by magmatic bodies and reacts at relatively high temperatures with surrounding rocks altering them and creating hydrocarbons without the influence of organisms or their organic products. This Faculty Early Career Development Project establishes an integrated research and education program at the University of Houston that is dedicated to improving our understanding of abiotic organic synthesis processes in seafloor hydrothermal systems, which have been proposed as possible sites for prebiotic organic synthesis and the origin of life on Earth. The reaction mechanisms and controlling factors of the resulting organic formation process will be studied in the laboratory at conditions analogous to those present in natural seafloor hydrothermal environments. Research will involve a combination of laboratory experiments, advanced analytical techniques for chemical and isotopic characterization, and a comparison of experimental results to samples from seafloor hydrothermal vents. Broader impacts of the work include tight integration of education and research activities designed to improve undergraduate and graduate education, with a focus of engaging students from minority groups, under-represented in the sciences, in the research program. It will also involve extensive interaction with the local Houston school district to reach out to middle and high school students to give them firsthand knowledge of how cutting edge geochemical research on the origin of life and generation of hydrocarbons is done. This will be accomplished via K-12 tours of the laboratory facilities and discussion with the researcher and his students on how these kinds of experiments are carried out and how the resulting data are analyzed and interpreted. Goals of this outreach are to raise students' awareness of science and how it is done and to motivate them into building careers in geosciences. Additional impacts include building infrastructure for science through the development of new analytical techniques and reactor design. Other impacts of the work include support an early career faculty member and has the potential to cross fields to inform and find application in the chemical and petroleum engineering fields.This research is fundamental to understanding the formation of abiotically generated organic molecules in seafloor hydrothermal systems. It will examine Fisher-Tropsch reactions associated with the abiotic generation of hydrocarbons. A laboratory experimental program that uses a novel reactor and state-of-the-art analytical methods will be carried out to study fluid-mineral-catalyzed organic synthesis at high temperatures and conditions similar to those in hydrothermal systems on mid-ocean ridges. Experimental charges will include natural minerals similar to those in seafloor environments; and experiments will focus on identifying reaction mechanisms that occur during organic synthesis. During the project, reaction mechanisms of abiotically generated organic compounds will be studied and systematic identification of molecular species in liquid, gas, and species adsorbed on mineral surfaces that are generated under a variety of physicochemical conditions in a state-of-the-art reactor system will be determined. Analytical work will include the use of gas chromatography-mass spectrometry, pyrolysis gas chromatographic mass spectrometry, nano-secondary ion mass spectrometry, and liquid chromatography-mass spectrometry. In addition, the carbon and hydrogen isotope signatures of newly generated organic compounds will be measured and the isotope signature of abiotically generated methane will be analyzed using the clumped isotope method to try to determine whether controlling factors affecting formation, other than temperature, are in play. In particular, compounds such as long chain hydrocarbons, homologous alkanes, alcohols, and carboxylic acids will be targeted because each is associated with a different reaction mechanism. Results of the laboratory experiments will be compared to the composition and physico-chemical conditions of formation of select vent fluid samples that were collected on oceanographic expeditions to mid-ocean ridge hydrothermal vents.