Tuning the Chemical Properties of Co–Ti 3 C 2 T x MXene Materials for Catalytic CO 2 Reduction

MXenes, a novel family of 2D materials, are energy materials that have gained considerable attention, particularly for their catalytic applications in emerging areas such as CO 2 and N 2 hydrogenation. Herein, for the first time, it is shown that the surface reducibility of Ti 3 C 2 T x MXene can be tuned by N doping, which induces a change in the catalytic properties of supported Co nanoparticles. Pristine Co–Ti 3 C 2 T x MXene favors CO production during CO 2 hydrogenation, whereas CH 4 production is favored when the MXene is subjected to simple N doping. X‐ray photoelectron spectroscopy and transmission electron microscopy (TEM) reveal that surface rutile TiO 2 nanoparticles appear on the Ti 3 C 2 T x support upon N doping, which interact strongly with the supported Co nanoparticles. This interaction alters the reducibility of the supported Co nanoparticles at the interface with the TiO 2 nanoparticles, shifting the product selectivity from CO to CH 4 . This study successfully showcases a practical strategy, based on surface chemistry modulation of 2D MXenes, for regulating product distribution in CO 2 hydrogenation.