Steering Cu-Based CO<sub>2</sub>RR Electrocatalysts’ Selectivity: Effect of Hydroxyapatite Acid/Base Moieties in Promoting Formate Production
Michele Ferri, Laurent Delafontaine, Shengyuan Guo, Tristan Asset, Pierangela Cristiani, Sebastiano Campisi, Antonella Gervasini, Plamen Atanassov
Abstract
Among all CO2 reduction reaction (CO2RR) active metals, copper is the only one that exhibits optimal *CO binding energy for multiple electron transfers. Despite such a unique feature, the use of Cu-based CO2RR catalysts at the industrial scale is hampered by large overpotentials and poor selectivity. In this realm, the introduction of acidic/basic functionalities at the catalyst surface may help to both overcome scaling relations (i.e., lower CO2RR overpotential) and tune the selectivity of Cu-based catalysts. Herein, we demonstrate that an amphoteric calcium phosphate additive (hydroxyapatite, HAP, Ca10(PO4)6(OH)2) alters the product distribution from Cu-based catalysts by steering CO2RR selectivity toward liquid oxygenated products, promoting formate production over CO.