Institute of Molecular Catalysis and In situ/operando Studies, College of Chemistry, Fuzhou University, Fujian, 350000, China.
Department of Chemical and Petroleum Engineering, University of Kansas, KS 66045, USA.
Chem Soc Rev. 2022 Jan 4;51(1):376-423. doi: 10.1039/d1cs00783a.
In the last few decades, worldwide scientists have been motivated by the promising production of chemicals from the widely existing methane (CH) under mild conditions for both chemical synthesis with low energy consumption and climate remediation. To achieve this goal, a whole library of catalytic chemistries of transforming CH to various products under mild conditions is required to be developed. Worldwide scientists have made significant efforts to reach this goal. These significant efforts have demonstrated the feasibility of oxidation of CH to value-added intermediate compounds including but not limited to CHOH, HCHO, HCOOH, and CHCOOH under mild conditions. The fundamental understanding of these chemical and catalytic transformations of CH under mild conditions have been achieved to some extent, although currently neither a catalyst nor a catalytic process can be used for chemical production under mild conditions at a large scale. In the academic community, over ten different reactions have been developed for converting CH to different types of oxygenates under mild conditions in terms of a relatively low activation or catalysis temperature. However, there is still a lack of a molecular-level understanding of the activation and catalysis processes performed in extremely complex reaction environments under mild conditions. This article reviewed the fundamental understanding of these activation and catalysis achieved so far. Different oxidative activations of CH or catalytic transformations toward chemical production under mild conditions were reviewed in parallel, by which the trend of developing catalysts for a specific reaction was identified and insights into the design of these catalysts were gained. As a whole, this review focused on discussing profound insights gained through endeavors of scientists in this field. It aimed to present a relatively complete picture for the activation and catalytic transformations of CH to chemicals under mild conditions. Finally, suggestions of potential explorations for the production of chemicals from CH under mild conditions were made. The facing challenges to achieve high yield of ideal products were highlighted and possible solutions to tackle them were briefly proposed.
在过去的几十年中，全球科学家一直受到在温和条件下从广泛存在的甲烷 (CH) 中生产化学物质的前景的激励，因为这既有利于低能耗的化学合成，也有利于气候修复。为了实现这一目标，需要开发一整套催化化学库，以在温和条件下将 CH 转化为各种产品。全球科学家为此付出了巨大努力。这些努力表明，在温和条件下，将 CH 氧化为有价值的中间化合物，包括但不限于 CHOH、HCHO、HCOOH 和 CHCOOH，是可行的。尽管目前既没有催化剂也没有催化过程可以在温和条件下大规模用于化学生产，但在温和条件下这些化学和催化转化的基本理解已经在一定程度上实现了。在学术界，已经开发了十多种不同的反应，用于在温和条件下将 CH 转化为不同类型的含氧化合物，其相对较低的活化或催化温度。然而，对于在温和条件下极其复杂的反应环境中进行的活化和催化过程，仍然缺乏分子水平的理解。本文综述了迄今为止对这些活化和催化的基本理解。通过平行审查 CH 的不同氧化活化或温和条件下的催化转化，确定了为特定反应开发催化剂的趋势，并获得了这些催化剂设计的见解。总的来说，本综述重点讨论了通过该领域科学家的努力获得的深刻见解。它旨在为温和条件下 CH 向化学物质的活化和催化转化提供一个相对完整的图景。最后，对温和条件下从 CH 生产化学品的潜在探索提出了建议。强调了实现理想产物高收率所面临的挑战，并简要提出了可能的解决方案。
