A Robust Pyridyl-NHC-Ligated Rhenium Photocatalyst for CO2 Reduction in the Presence of Water and Oxygen
A Robust Pyridyl-NHC-Ligated Rhenium Photocatalyst for CO2 Reduction in the Presence of Water and Oxygen
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DOI：
10.3390/inorganics6010022
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发表时间：
2018-03-01
期刊：
影响因子：
2.9
通讯作者：
Delcamp, Jared H.
中科院分区：
文献类型：
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作者：
Carpenter, Casey A.;Brogdon, Phillip;Delcamp, Jared H.
Re（pyNHC-PhCF 3）（CO）（3）Br是一种高效的CO2还原光催化剂。PhCF 3衍生物先前根据经验显示为稳健的催化剂。在这里，PhCF 3基团的作用进行了计算探测，并分析了这种催化剂的鲁棒性，在可见光下将CO2光催化还原为CO的过程中，以受控量引入的水和氧的存在。发现该络合物在0-1%水浓度下可再现地工作良好;然而，基准Re（bpy）（CO）（3）Cl需要痕量的水以提供可再现的反应性。当向反应混合物中加入环境空气时，发现NHC络合物在高达40%的环境气氛和60%CO2下保持基本的性能（类似于50%的优化反应性），而发现Re（bpy）（CO）（3）Cl络合物在引入环境气氛时产生显著降低的CO2还原反应性。通过使用时间相关的单光子计数研究和先前的电化学结果，我们推断这种增强的催化剂弹性是由于NHC和bpy基催化剂之间的机理差异。这些结果突出了这种NHC-配位催化剂的一个重要特征：对常见反应污染物的稳定性显著增强。
Re(pyNHC-PhCF3)(CO)(3)Br is a highly active photocatalyst for CO2 reduction. The PhCF3 derivative was previously empirically shown to be a robust catalyst. Here, the role of the PhCF3 group is probed computationally and the robust nature of this catalyst is analyzed with regard to the presence of water and oxygen introduced in controlled amounts during the photocatalytic reduction of CO2 to CO with visible light. This complex was found to work well from 0-1% water concentration reproducibly; however, trace amounts of water were required for benchmark Re(bpy)(CO)(3)Cl to give reproducible reactivity. When ambient air is added to the reaction mixture, the NHC complex was found to retain substantial performance (similar to 50% of optimized reactivity) at up to 40% ambient atmosphere and 60% CO2 while the Re(bpy)(CO)(3)Cl complex was found to give a dramatically reduced CO2 reduction reactivity upon introduction of ambient atmosphere. Through the use of time-correlated single photon counting studies and prior electrochemical results, we reasoned that this enhanced catalyst resilience is due to a mechanistic difference between the NHC- and bpy-based catalysts. These results highlight an important feature of this NHC-ligated catalyst: substantially enhanced stability toward common reaction contaminates.