Enhanced CO2 Conversion into Ethanol by Permanently Polarized Hydroxyapatite through C−C Coupling

Abstract Hydroxyapatite (HAp) is a naturally occurring mineral form of calcium apatite of biomedical importance due to its similarity with human hard tissues in morphology and composition. Upon polarization at high temperature, applying 3 kV/cm at 1000 °C, the resulting polarized HAp (p‐HAp) exhibits enhanced catalytic behavior due charge accumulation at the interface. More specifically, p‐HAp was found to catalyse the conversion of mixtures of CO 2 (g) and CH 4 (g) into low carbon organic molecules and into amino acids when N 2 (g) was added to the mixture. In this work, we report how p‐HAp facilitates the conversion of CO 2 (g) mainly in ethanol by means of forming C−C coupled bonds on its activated surface. After evaluation of a wide range of experimental conditions, we evidence the production of formic acid, methanol and formaldehyde (C1 products); ethanol and acetic acid (C2 products); and acetone (C3 product) from CO 2 (g) using moderate reaction conditions. Moreover, optimization of the reaction parameters led to a significant increase towards ethanol.