Tuning the Chemical Properties of Co-Ti3C2Tx MXene Materials for Catalytic CO2 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 CO2 and N-2 hydrogenation. Herein, for the first time, it is shown that the surface reducibility of Ti3C2Tx MXene can be tuned by N doping, which induces a change in the catalytic properties of supported Co nanoparticles. Pristine Co-Ti3C2Tx MXene favors CO production during CO2 hydrogenation, whereas CH4 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 TiO2 nanoparticles appear on the Ti3C2Tx 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 TiO2 nanoparticles, shifting the product selectivity from CO to CH4. This study successfully showcases a practical strategy, based on surface chemistry modulation of 2D MXenes, for regulating product distribution in CO2 hydrogenation.

Automated summary

This study demonstrates that the surface reducibility of Ti3C2Tx MXene can be tuned by N doping, leading to a change in the catalytic properties of supported Co nanoparticles. Pristine Co-Ti3C2Tx MXene favors CO production during CO2 hydrogenation, whereas CH4 production is favored when the MXene is subjected to N doping.