Tailoring the catalytic performance of MXenes in propane dehydrogenation by layer substitution from microkinetic simulations

The reactivity and catalytic performance of MXenes in propane dehydrogenation (PDH) are highly dependent on their composition. This study explores modifying MXenes by substituting their X-layers with carbon, nitrogen, or a mix of both. Density functional theory (DFT) and microkinetic simulations show that these substitutions substantially alter the catalytic mechanism. Nitrogen substitution shifts the p-band center of oxygen active sites closer to the Fermi level, significantly lowering the energy barrier for the first C−H bond activation. Microkinetic analysis further confirms that nitrogen-substituted MXenes exhibit the highest turnover frequency (TOF) for propane conversion and propylene formation. The findings demonstrate that PDH reactivity can be precisely tuned by X-layer substitution, offering a strategy for optimizing MXene-based catalysts.