Rollier Floriane A, Muravev Valery, Kosinov Nikolay, Wissink Tim, Anastasiadou Dimitra, Ligt Bianca, Barthe Laurent, Costa Figueiredo Marta, Hensen Emiel J M
Laboratory of Inorganic Materials and Catalysis, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
Synchrotron SOLEIL L'Orme des Merisiers, Départementale 128 91190 Saint-Aubin France.
J Mater Chem A Mater. 2024 Dec 5;13(3):2285-2300. doi: 10.1039/d4ta04263h. eCollection 2025 Jan 14.
The electroreduction of CO (CORR) is a promising alternative to the direct CO electroreduction reaction (CO2RR) to produce C products. Cu-based electrocatalysts enable the formation of C-C bonds, leading to various C hydrocarbon and oxygenate products. Herein, we investigated how the composition of bimetallic Cu-Ag catalysts impacted the nature of the Cu-Ag interactions and the product distribution of the CORR, aiming to improve the selectivity to C products. Cu-Ag catalysts containing 1-50 mol% Ag were prepared by sol-gel synthesis. A Ag content of 10 mol% of Ag (CuAg) was optimum with respect to increasing the C product selectivity and suppressing H evolution. X-ray absorption spectroscopy and quasi- X-ray photoelectron spectroscopy demonstrated the complete reduction of CuO to Cu during CORR. Electron microscopy (EM) and wide-angle X-ray scattering (WAXS) revealed substantial restructuring during reduction. EM imaging showed the formation of Ag-Cu core-shell structures in CuAg, while separate Cu and Ag particles were predominant at higher Ag content. WAXS revealed the formation of a Cu-Ag nanoalloy phase in the bimetallic Cu-Ag samples. The optimum CuAg sample contained more Cu-Ag nanoalloys than samples with a higher Ag content. The Cu-Ag interfaces between the Ag-core and the Cu-shell in the bimetallic particles are thought to host the nanoalloys. The optimum CORR performance for CuAg is likely due to the enhanced Cu-Ag interactions, as confirmed by a sample prepared with the same surface composition by galvanic exchange.
一氧化碳的电还原反应（CORR）是一种有前景的替代直接二氧化碳电还原反应（CO2RR）来生产含碳产物的方法。铜基电催化剂能够形成碳-碳键，从而生成各种碳氢化合物和含氧化合物产物。在此，我们研究了双金属铜-银催化剂的组成如何影响铜-银相互作用的性质以及CORR的产物分布，旨在提高对含碳产物的选择性。通过溶胶-凝胶合成法制备了含1-50 mol%银的铜-银催化剂。就提高含碳产物选择性和抑制析氢而言，10 mol%银含量的银（CuAg）是最佳的。X射线吸收光谱和准X射线光电子能谱表明，在CORR过程中氧化铜完全还原为铜。电子显微镜（EM）和广角X射线散射（WAXS）显示在还原过程中有大量的结构重组。EM成像显示在CuAg中形成了银-铜核壳结构，而在较高银含量时，单独的铜和银颗粒占主导。WAXS揭示了在双金属铜-银样品中形成了铜-银纳米合金相。最佳的CuAg样品比高银含量的样品含有更多的铜-银纳米合金。双金属颗粒中银核与铜壳之间的铜-银界面被认为是纳米合金的所在之处。CuAg的最佳CORR性能可能归因于增强的铜-银相互作用，这通过通过电偶交换制备的具有相同表面组成的样品得到了证实。
