MXenes as promising catalysts for water dissociation

authors	Gouveia, JD; Morales-Garcia, A; Vines, F; Illas, F; Gomes, JRB
nationality	International
journal	APPLIED CATALYSIS B-ENVIRONMENTAL
author keywords	Water gas shift reaction; 2D materials; Carbides; Nitrides; Density functional theory; Periodic models
keywords	GAS SHIFT REACTION; DENSITY-FUNCTIONAL THEORY; MOLYBDENUM CARBIDE; MECHANISM; SURFACES; GOLD; HYDROGENATION; NANOPARTICLES; ADSORPTION; NANOSHEETS
abstract	Two-dimensional few-layered transition-metal nitrides and carbides, called MXenes, have attracted a great interest given their large surface areas and their unique physicochemical properties. Motivated by the known reactivity of surfaces of bulk transition metal carbides on the mechanism behind the water-gas shift (WGS) reaction, density functional theory (DFT) calculations were employed to investigate the bonding of water and its dissociation on a set of eighteen M2X MXene (M = Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, while X = C or N) surfaces. Here it is shown that all the studied MXenes exothermically adsorb water, with adsorption energies ranging from -1.43 to -2.94 eV, and greatly facilitate its dissociation, with energy barriers below 0.44 eV. These results reinforce the role of MXenes in promoting water dissociation, effectively suggesting their potential as catalysts for industrially relevant processes such as the WGS reaction.
publisher	ELSEVIER
issn	0926-3373
isbn	1873-3883
year published	2020
volume	260
digital object identifier (doi)	10.1016/j.apcatb.2019.118191
web of science category	Chemistry, Physical; Engineering, Environmental; Engineering, Chemical
subject category	Chemistry; Engineering
unique article identifier	WOS:000496894300051