Is the Surface Playing a Role during Pyridine-Catalyzed CO2 Reduction on p-GaP Photoelectrodes?
Is the Surface Playing a Role during Pyridine-Catalyzed CO2 Reduction on p-GaP Photoelectrodes?
复制标题
DOI：
10.1021/acsenergylett.6b00233
复制
发表时间：
2016-08-01
影响因子：
22
通讯作者：
Carter, Emily A.
中科院分区：
文献类型：
--
作者：
Lessio, Martina;Senftle, Thomas P.;Carter, Emily A.
光电极表面在吡啶催化的CO2还原过程中的作用目前仍有争议。了解光电极直接参与催化CO还原机理的程度对于改进此类光电化学系统的设计是至关重要的。在这里，我们提出了新的理论结果表明，以前提出的吡啶基自由基中间体是不可能形成的，并减少吡啶吸附吡啶和H物种仍然是最有利的还原途径，即使当占水环境。此外，我们得出结论，根据最近报道的实验证据和我们的新的计算结果，在这个系统中运行的CO，还原机制可能是异质的。我们还介绍了一个新的多相机制，涉及最近提出的自由基物种，我们预测将是稳定的电极表面上，并可能作为该系统中的活性催化物种。
The role of the photoelectrode surface during pyridine-catalyzed CO, reduction on p-GaP photocathodes is currently under debate. Understanding the extent of the photoelectrode's direct participation in the catalytic CO, reduction mechanism is essential to improving the design of such photoelectrochemical systems. Here, we present new theoretical results demonstrating that the previously proposed pyridinyl radical intermediate is unlikely to form and that reduction of pyridinium to adsorbed pyridine and H species remains the most favorable reduction pathway, even when accounting for the aqueous environment. Furthermore, we conclude, based on recently reported experimental evidence and our new computational results reported herein, that the mechanism of CO, reduction operating in this system is likely heterogeneous. We also introduce a new heterogeneous mechanism involving a recently proposed radical species, which we predict will be stable on the electrode surface and that may serve as the active catalytic species in this system.