Multiscale Modeling Strategy for Enhancing Electrocatalytic Activities of CuPd Alloy Nanoparticles Generated on Cu(111) Facet for C–N Coupling in Induced [Bmim][BF4] Ionic Liquid and pH-Dependent Microenvironments

The tandem electrocatalytic reduction of carbon dioxide (CO2) and nitrate (NO3–) produces high-value organonitrogen compounds via C–N coupling. This strategy is effective for carbon-neutralization and environmental pollution control, especially for acetamide and urea synthesis applications, which are attracting increasing attention. However, the C–N coupling reaction in this technological process still presents many challenges, the most important of which are addressing the low C–N coupling efficiency and selectivity of the target products and identifying the key intermediates and catalytic mechanism. Fortunately, C–N coupling can occur between ketene (*CCO) and ammonia (NH3) or carbon monoxide (*CO) and hydroxylamine (NH2OH), as has been identified by experiment. The coupling of *CCO and NH3 forms a *CC(OH)NH2 intermediate via nucleophilic attack. Copper–palladium (CuPd) nanoparticles (NPs), a potential class of catalysts derived from the Cu(111) facet via Cu/Pd thermal reduction, have recently attracted extensive attention because of their promising electrochemical properties, which make them potential electrocatalysts for the CO2 reduction reaction (CO2RR) and expand the applications of Cu-based materials. We modeled the electrode double layer (EDL) at the CuPd catalyst interface, which was modulated using 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) ionic liquid (IL) and a pH-dependent (acidic, neutral, and alkaline) microenvironment. We included a series of anions and cations to study their electrode potentials. The [Bmim]+ cation played a crucial role in enriching local CO2 and stabilizing carbon-based intermediates. Our density functional theory (DFT) calculations showed limiting potentials of −0.97 (neutral) and −0.71 V (acidic) for producing acetamide and urea on CuPd NPs, respectively, indicating remarkable CO2-integrated NO3– coreduction activity to acetamide and urea. Furthermore, the ab initio molecular dynamics (AIMD) method was employed to examine the effect of the solvent layer on reaction intermediates by investigating the dynamic structural evolution of O–H and C═O bond length variations under realistic CO2RR conditions. The results showed that CuPd NPs remained stable after 10 ps of simulated time in a pH-dependent microenvironment with [Bmim][BF4] at 300 K. The pH-dependent microenvironment with [Bmim][BF4] plays an important role in designing high-performance catalysts for both C–N and C–C coupling over CuPd NPs catalyst.