Catalytic Mechanisms in Transition Metal Carbides

Transition metal carbides (TMCs) occupy a unique position in heterogeneous catalysis, combining metallic conductivity with covalent character to enable efficient activation of small molecules. Their d-band electron density facilitates strong binding and back-donation to adsorbates such as CO₂, H₂ and CO, while remaining resistant to sintering and deactivation. Surface terminations and stoichiometry can be tuned to modulate adsorption energies, electronic structure and reaction pathways. Key processes include the reverse water–gas shift reaction, CO₂ hydrogenation to CO, methanol or higher hydrocarbons, and dry reforming of methane. TMCs also serve as supports for noble and base metal clusters, inducing strong metal–support interactions that stabilise active sites and alter reaction selectivity. Collectively, these features underpin global efforts to develop sustainable routes for carbon capture, utilisation and clean fuel production.

Research from Nature Portfolio

Recent studies have demonstrated that, under reverse water–gas shift conditions, the surface of molybdenum nitride undergoes product-induced restructuring into molybdenum carbide. Carbon monoxide and water formed in the reaction induce surface carbonisation of MoNx to MoCx at elevated pressures, creating more active carbide sites. This positive feedback between catalytic activity and catalyst activation highlights how dynamic surface transformations can enhance reaction rates and suggests a general strategy for in situ generation of active TMC phases.

Catalytic Mechanisms in Transition Metal Carbides publication trend

The graph below shows the total number of articles in catalytic mechanisms in transition metal carbides across all publications each year (not limited to Nature Index journals).

Technical terms

Transition metal carbide (TMC): A compound of a transition metal and carbon, exhibiting combined metallic and covalent bonding that favours catalytic activity.

Reverse water–gas shift (RWGS): A reaction that converts carbon dioxide and hydrogen into carbon monoxide and water, often used to generate syngas.

MXene: A family of two-dimensional transition metal carbides or nitrides derived from layered precursors, notable for high surface areas and tunable chemistries.

Eley–Rideal mechanism: A surface reaction pathway in which a gas-phase species reacts directly with an adsorbed intermediate on the catalyst surface.

Strong metal–support interaction (SMSI): An effect whereby the support modifies the electronic or structural properties of metal nanoparticles, enhancing their stability and catalytic performance.

References

1. Reverse water gas-shift reaction product driven dynamic activation of molybdenum nitride catalyst surface. Nature Communications (2024).
2. Preparation of nano Cu-Mo2C interface supported on ordered mesoporous biochar of ultrahigh surface area for reverse water gas shift reaction. Biochar (2024).
3. Molecular Mechanism and Microkinetic Analysis of the Reverse Water Gas Shift Reaction Heterogeneously Catalyzed by the Mo2C MXene. ACS Catalysis (2022).
4. Bulk and surface properties of metal carbides: implications for catalysis. Physical Chemistry Chemical Physics (2018).