Krishnan Murugan, Vijayaprabhakaran Aathilingam, Kathiresan Murugavel
Electro Organic & Materials Electrochemistry Division, CSIR-Central Electrochemical Research Institute, Karaikudi - 630003, Tamil Nadu, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad - 201002, India.
Nanoscale. 2024 Aug 29;16(34):16218-16226. doi: 10.1039/d4nr01122h.
Transforming carbon dioxide (CO) into valuable chemicals electroreduction presents a sustainable and viable approach to mitigating excess CO in the atmosphere. This report provides fresh insights into the design of a new titanium-based MXene composite as a catalyst for the efficient conversion of CO in a safe aqueous medium. Despite its excellent electrocatalytic activity towards CO reduction and high selectivity for CO production, the high cost of Au and the decline in catalytic activity on a larger scale hinder its large-scale CO conversion applications. In this research, we have successfully prepared an Au/TiCT composite and tested its catalytic activity in the electrochemical CO reduction reaction (ECRR). The as-prepared composite features strong interactions between gold atoms and the MXene support, achieved through the formation of metal-oxygen/carbon bonds. The Au/TiCT electrode demonstrated a significant current density of 17.3 mA cm at a potential of -0.42 V RHE, in a CO saturated atmosphere (faradaic efficiency: CO = 48.3% and H = 25.6%). Nyquist plots further indicated a reduction in the charge-transfer resistance of the Au/TiCT layer, signifying rapid charge transfer between the Au and TiCT. Furthermore, it is known that liquid crossover through the Gas Diffusion Electrode (GDE) significantly improves CO diffusion to catalyst active sites, thereby enhancing CO conversion efficiency. The goal of this work is to design an interface between metal and MXene so that CO can be electroreduced to fuels and other useful chemical compounds with great selectivity.
将二氧化碳（CO₂）电还原为有价值的化学品是一种可持续且可行的方法，有助于减少大气中过量的CO₂。本报告为一种新型钛基MXene复合材料的设计提供了新见解，该复合材料可作为在安全水性介质中高效转化CO₂的催化剂。尽管金对CO₂还原具有优异的电催化活性且对CO生成具有高选择性，但金的高成本以及大规模应用时催化活性的下降阻碍了其大规模CO₂转化应用。在本研究中，我们成功制备了Au/Ti₃C₂Tₓ复合材料，并测试了其在电化学CO₂还原反应（ECRR）中的催化活性。所制备的复合材料通过形成金属-氧/碳键，在金原子与MXene载体之间具有强相互作用。在CO饱和气氛中，Au/Ti₃C₂Tₓ电极在相对于可逆氢电极（RHE）为-0.42 V的电位下表现出17.3 mA cm⁻²的显著电流密度（法拉第效率：CO = 48.3%，H₂ = 25.6%）。奈奎斯特图进一步表明Au/Ti₃C₂Tₓ层的电荷转移电阻降低，这意味着金与Ti₃C₂Tₓ之间的快速电荷转移。此外，已知通过气体扩散电极（GDE）的液体交叉显著改善了CO向催化剂活性位点的扩散，从而提高了CO₂转化效率。这项工作的目标是设计金属与MXene之间的界面，以便CO₂能够以高选择性电还原为燃料和其他有用的化合物。
