Ultrasmall palladium nanoparticles supported on zirconium phosphate for electrochemical CO2 reduction to ethanol

Abstract

The electrochemical CO₂ reduction reaction (CO₂RR) provides a promising approach to mitigate the global greenhouse effect by converting CO₂ into high-value chemicals or fuels. Noble metal-based nanomaterials are widely regarded as efficient catalysts for CO₂RR due to their high catalytic activity and excellent stability. However, these catalysts typically favor the formation of C1 products, which have relatively low economic value. Moreover, the high cost and limited availability of noble materials necessitate strategies to reduce their usage, often by dispersing them on suitable support materials to enhance catalytic performance. In this study, a novel metal-based support, zirconium phosphate Zr₃(PO₄)₄, was used to anchor ultrasmall palladium nanoparticles (pre-ZrP-Pd). Compared to the reversible hydrogen electrode, the pre-ZrP-Pd achieved a maximum Faradaic efficiency (FE) of 92.1% for ethanol at −0.8 V versus RHE, along with a peak ethanol current density of 0.82 mA/cm². Density functional theory (DFT) calculations revealed that the strong metal-support interactions between the ZrP support and Pd nanoparticles lead to an upward shift of the Pd d-band center, enhancing the adsorption of CO* and promoting the coupling of CO and CO to produce ethanol.