Discovery and design of tri-metallic structure electrocatalysis for prompting c-c bond formation in the electrochemical reduction of CO 2 Shahid Rasul 1 , Ian Brewis 1 , Abdesslem Jedidi 2 1 Northumbria University, UK, 2 King Abdul Aziz University, Kingdom of Saudi Arabia electrocatalysts in improving the selectivity of the CO 2 reduction reaction (CO2RR) toward multi-carbon compounds. Through tailored deposition of sub-surface platinum (Pt), it has been observed that the selectivity of previously cutting-edge bimetallic electrocatalysts such as Cu-In and Cu-Sn can be tuned to a specific product range, stabilising carbonaceous intermediates to promote the formation of C2+ hydrocarbons. Experimental results, supported by Density functional theory (DFT) studies, demonstrate how incorporating small quantities of Pt can improve the adsorption strength of multi-carbon intermediates. Such changes are likely due to the strong binding energy of Pt, diluted to such a degree by neighbouring Cu and In so as to prevent over-binding of CO, preventing poisoning of active sites whilst opening an effective pathway to higher order reduction products. Through improved stabilisation of intermediates such as CO*, OCCOH* and CH3CHO, all shown to be key in proposed C3 pathways [3, 4] , Cu-In-Pt and Cu-Sn-Pt electrocatalysts may even pose a core role in the formation of energy-dense products such as n-propanol (C3H8O) and allyl alcohol (C3H6O) through the promotion of C-C bonds. The lack of availability of efficient, selective, and stable electrocatalysts is a major hindrance to the scalability of the CO 2 reduction processes [1-2] .Herein, we report a pioneering study into the key role of tri-metallic We further explore the promotional effects of Pt doping through DFT based studies into the preferential adsorption sites for both CO and H, both of which hold rate-limiting steps for CO2RR and the competing hydrogen evolution reaction (HER), on Cu-In and Cu-Sn surfaces. Results demonstrate how for the case of neighbouring Cu, In and Pt, hydrogen remains hindered due to the hydrophobicity of In, whilst demonstrating improved CO adsorption of up to ~0.5eV, providing a more attractive environment for the formation of C-C bonds. Through both experimental and computational means, we reveal insights into state-of-the-art catalyst design, producing materials favourable toward the formation of multi-carbon compounds whilst continuing to suppress the competing HER reaction. References 1. Jedidi, A., Rasul, S., Masih, D., Cavallo, L., & Takanabe, K. (2015). Generation of Cu-In alloy surfaces from CuInO2 as selective catalytic sites for CO2 electroreduction. Journal of Materials Chemistry A, 3(37), 19085–19092. 2. Rasul, S., Anjum, D. H., Jedidi, A., Minenkov, Y., Cavallo, L., & Takanabe, K. (2015). A highly selective copper-indium bimetallic electrocatalyst for the electrochemical reduction of aqueous CO2to CO. Angewandte Chemie - International Edition, 54(7), 2146–2150. 3. Garza, A. J., Bell, A. T., & Head-Gordon, M. (2018). Mechanism of CO2 Reduction at Copper Surfaces: Pathways to C2 Products. ACS Catalysis, 8(2), 1490–1499. 4. Tang, M. T., Peng, H. J., Stenlid, J. H., & Abild-Pedersen, F. (2021). Exploring Trends on Coupling Mechanisms toward C3Product Formation in CO(2)R. Journal of Physical Chemistry C, 125(48), 26437–26447. https://doi.org/10.1021/acs. jpcc.1c07553
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