大气中二氧化碳含量的不断增加导致了全球变暖。将二氧化碳转化为其他碳化合物可以减轻其大气水平并生产有价值的产品,作为CO2也可以作为丰富和廉价的碳原料。然而,CO2的惰性性质对其减少提出了重大挑战。为了迎接挑战,自然界利用Fe等过渡金属离子进化出金属酶,Ni,Mo,W,以及电子转移伙伴的功能。模仿这些酶,人工金属酶(ArM)已经设计使用替代蛋白质支架和各种金属因子,如Ni,Co,Re,Rh,和FeS簇。在过去的十年中,这些ArM的催化效率和CO2还原产物的范围都得到了改善。这篇综述首先集中于通过讨论它们的结构和活性位点直接减少CO2的天然金属酶,以及所提出的反应机理。然后介绍了电化学的常用策略,光化学,或光电化学利用这些天然酶来减少CO2,并突出了过去五年的最新进展。我们还总结了生物启发Arm的蛋白质设计原理,将它们与天然酶系统进行比较,并概述了酶促CO2还原的挑战和机遇。
The continuously increasing level of atmospheric CO2 in the atmosphere has led to global warming. Converting CO2 into other carbon compounds could mitigate its atmospheric levels and produce valuable products, as CO2 also serves as a plentiful and inexpensive carbon feedstock. However, the inert nature of CO2 poses a major challenge for its reduction. To meet the challenge, nature has evolved metalloenzymes using transition metal ions like Fe, Ni, Mo, and W, as well as electron-transfer partners for their functions. Mimicking these enzymes, artificial metalloenzymes (ArMs) have been designed using alternative protein scaffolds and various metallocofactors like Ni, Co, Re, Rh, and FeS clusters. Both the catalytic efficiency and the scope of CO2-reduction product of these ArMs have been improved over the past decade. This review first focuses on the natural metalloenzymes that directly reduce CO2 by discussing their structures and active sites, as well as the proposed reaction mechanisms. It then introduces the common strategies for electrochemical, photochemical, or photoelectrochemical utilization of these native enzymes for CO2 reduction and highlights the most recent advancements from the past five years. We also summarize principles of protein design for bio-inspired ArMs, comparing them with native enzymatic systems and outlining challenges and opportunities in enzymatic CO2 reduction.