Yadav Radhey Shyam, Kashyap Diwakar, Pitussi Itay, Gebru Medhanie Gebremedhin, Teller Hanan, Schechter Alex, Kornweitz Haya
Department of Chemical Sciences, Ariel University, Ariel 40700, Israel.
Research and Development Centre for Renewable Energy, New Technology Centre, University of West Bohemia, 301 00 Pilsen, Czech Republic.
ACS Appl Mater Interfaces. 2024 Oct 30;16(43):58573-58586. doi: 10.1021/acsami.4c11282. Epub 2024 Oct 16.
The shift toward renewable energy sources plays a central role in the quest for a circular economy. In this context, methyl formate (MF) has garnered attention as a compelling hydrogen carrier and alternative fuel, because of its remarkable characteristics (energy density, ease of storage and transport, and low boiling point). In this study, DFT calculations supported by online electrochemical mass spectroscopy (OE-MS) were performed to investigate the MF electro-oxidation (MFEO) on PtPdSn (111). The DFT calculations provide insight into the role of Pt, Pd, and Sn atoms in MFEO. Pt and Pd together provide a preferred active site for initiating MFEO through the O-H bond scission, and Sn plays an essential role in the mitigation of CO through oxygenation or water activation. By comparing the reaction energies and activation barriers for all possible reactions in MFEO, the suggested path necessitates a minimum energy of 0.14 eV to initiate the MFEO. This value was supported by the experimental results, showing that the oxidation wave of MF starts at 0.15 V (70 °C). Density functional theory (DFT) results, supported by OE-MS, indicate that the hydrolysis of MF prior to MFEO is not preferred on PtPdSn (111) surfaces, although the formation of methanol is plausible via a CHO intermediate. Among the three small organic molecules (SOMs) studied─MF, methanol, and formic acid─MF has the lowest activation energy for the initial bond breaking that starts the whole oxidation process (0.13 eV), compared to formic acid (0.45 eV) and methanol (0.61 eV); thus, MF is the preferred fuel on PtPdSn (111).
向可再生能源的转变在寻求循环经济中起着核心作用。在这种背景下，甲酸甲酯（MF）因其显著特性（能量密度、易于储存和运输以及低沸点）而作为一种引人注目的氢载体和替代燃料受到关注。在本研究中，进行了在线电化学质谱（OE-MS）支持的密度泛函理论（DFT）计算，以研究PtPdSn（111）上的MF电氧化（MFEO）。DFT计算深入了解了Pt、Pd和Sn原子在MFEO中的作用。Pt和Pd共同为通过O-H键断裂引发MFEO提供了一个优选的活性位点，并且Sn在通过氧化或水活化减轻CO方面起着至关重要的作用。通过比较MFEO中所有可能反应的反应能量和活化能垒，所提出的路径启动MFEO需要的最小能量为0.14 eV。该值得到了实验结果的支持，实验结果表明MF的氧化波在0.15 V（70°C）开始。由OE-MS支持的密度泛函理论（DFT）结果表明，尽管通过CHO中间体形成甲醇是合理的，但在PtPdSn（111）表面上，MFEO之前的MF水解并不占优势。在所研究的三种小有机分子（SOMs）——MF、甲醇和甲酸中，与甲酸（0.45 eV）和甲醇（0.61 eV）相比，MF在启动整个氧化过程的初始键断裂方面具有最低的活化能（0.13 eV）；因此，MF是PtPdSn（111）上的优选燃料。
