Synthesis of Cu2O@Cu-Fe-K Prussian Blue analogue core–shell nanocube for enhanced electroreduction of CO2 to multi-carbon products

[Display omitted] •Cu2O@Cu-Fe-K PBA was prepared by a template-engaged redox deposition approach.•Cu2O@Cu-Fe-K PBA serves as an efficient CO2ER catalyst to promote the C2+ products.•Fe and K elements can modulate the interface engineering of Cu2O surface. Cu2O@Cu-Fe-K Prussian Blue analogue (K-PBA) core–shell nanocube was synthesized by a facile template-engaged redox deposition approach, and could be used as an efficient catalyst for CO2 electrochemical reduction (CO2ER). The presence of K-PBA shell not only can protect the Cu2O active core, but also promote the ratios of multi-carbon products to competing methane in CO2ER, achieving a total C2+ Faradaic efficiency (FE) of 23.9% (ethylene 10.8%, ethanol 3.6% and n-propanol 9.5%) at −1.11 V (vs. reversible hydrogen electrode (RHE), while jtotal = 6.2 mA cm−2. It is suggested that K-PBA shell coating alter inherent adsorption energetics of Cu2O, which contributes to the C–C coupling step in CO2ER.