Visible Light Driven Hydrogen Evolution by Molecular Nickel Catalysts with Time-Resolved Spectroscopic and DFT Insights.
Visible Light Driven Hydrogen Evolution by Molecular Nickel Catalysts with Time-Resolved Spectroscopic and DFT Insights.
复制标题
具有时间分辨光谱和 DFT 见解的分子镍催化剂的可见光驱动析氢。
作者：
Xian Liang Ho;Haiyan Shao;Yik Yie Ng;Rakesh Ganguly;Yunpeng Lu;Han Sen Soo
氢（H2）是一种清洁燃料，可能成为未来间歇性可再生能源存储的解决方案。然而，目前的H2生产主要由能量密集型蒸汽重整反应主导，其消耗化石燃料甲烷，并排放大量的二氧化碳作为副产物之一。为了应对这一挑战，我们报告了一种分子催化剂，它可以从水溶液中产生H2，由价格合理的地球上丰富的元素（如镍）组成，并已被纳入由可见光驱动的系统中。在优化的条件下，我们观察到的营业额为3880，其中最好的光催化H2的演变与镍配合物从水-甲醇溶液。通过纳秒瞬态吸收，电子顺磁共振，紫外-可见光谱测量，并支持密度泛函理论计算，我们报告了详细的研究，这种光催化H2的演变周期。我们证明，一个电子减少，主要是配体为中心的，反应性镍中间体可以在可见光照射下使用三乙胺作为牺牲电子供体和还原淬灭剂的初始光敏剂激发态。此外，计算结果表明，第二配位球醚臂可以通过促进质子传递来提高催化活性，类似于自然界中[FeFe]氢化酶的机理.我们的研究可以形成H2进化分子催化剂的未来发展的基础，将配体氧化还原noninnocent和替代的第二配位球效应在人工光合作用系统驱动的可见光。
Hydrogen (H2) is a clean fuel that can potentially be a future solution for the storage of intermittent renewable energy. However, current H2 production is mainly dominated by the energy intensive steam reforming reaction, which consumes a fossil fuel, methane, and emits copious amounts of carbon dioxide as one of the byproducts. To address this challenge, we report a molecular catalyst that produces H2 from aqueous solutions, is composed of affordable, earth-abundant elements such as nickel, and has been incorporated into a system driven by visible light. Under optimized conditions, we observe a turnover number of 3880, among the best for photocatalytic H2 evolution with nickel complexes from water-methanol solutions. Through nanosecond transient absorption, electron paramagnetic resonance, and UV-vis spectroscopic measurements, and supported by density functional theory calculations, we report a detailed study of this photocatalytic H2 evolution cycle. We demonstrate that a one-electron reduced, predominantly ligand-centered, reactive Ni intermediate can be accessed under visible light irradiation using triethylamine as the sacrificial electron donor and reductive quencher of the initial photosensitizer excited state. In addition, the computational calculations suggest that the second coordination sphere ether arms can enhance the catalytic activity by promoting proton relay, similar to the mechanism among [FeFe] hydrogenases in nature. Our study can form the basis for future development of H2 evolution molecular catalysts that incorporate both ligand redox noninnocence and alternative second coordination sphere effects in artificial photosynthetic systems driven by visible light.
影响因子：
62.1
作者：
Prier, Christopher K.;Rankic, Danica A.;MacMillan, David W. C.
通讯作者：
MacMillan, David W. C.
影响因子：
16.6
作者：
Pfeffer, Michael G.;Kowacs, Tanja;Rau, Sven
通讯作者：
Rau, Sven