Low Temperature Sunlight‐Powered Reduction of CO<sub>2</sub> to CO Using a Plasmonic Au/TiO<sub>2</sub> Nanocatalyst
Pau Martínez Molina, Nicole Meulendijks, Man Xu, Marcel A. Verheijen, Tim den Hartog, Pascal Buskens, Francesc Sastre
Abstract
Abstract Sunlight‐powered reduction of CO 2 to fuels and chemicals is a promising strategy to close the carbon loop and facilitate the energy transition. In this research, we demonstrate that Au nanoparticles supported on TiO 2 are an efficient plasmonic catalyst for the sunlight‐powered reverse water‐gas shift (rWGS) reaction. A maximum CO production rate of 429 mmol ⋅ g Au −1 ⋅ h −1 with a selectivity of 98 % and an apparent quantum efficiency of 4.7 % were achieved using mildly concentrated sunlight (1.44 W ⋅ cm −2 equals 14.4 sun). The CO production rate showed an exponential increase with increasing light intensity, suggesting that the process is mainly promoted by a photothermal effect. Thermal reference experiments with the same catalysts promoted CH 4 formation, dropping the CO selectivity to 70 %. Thus, mildly concentrated sunlight can efficiently and selectively enhance the promotion of the rWGS reaction without using external heating.