Theoretical study of catalytic performance of α-molybdenum carbide modified with Fe, Co, Ni and Cu for hydrogen evolution reaction

Presently, the majority of the actual energy demand is met with fossil fuels. However, because of the constantly rising price of energy sources and increasing demand for them, energy production is becoming one of the biggest concerns of modern civilization. Solar energy is a good example of available alternative energy sources, however its usage requires an efficient way of energy storage. Hydrogen is a very promising candidate because of its high energy density. In 1973 Levi and Boudart reported that tungsten carbide possesses catalytic activity for hydrogenation reactions similar to activity of platinum and since then transition metals carbides came into focus of scientific community.
Interaction of H and H2 with TMC are well studied, both experimentally and theoretically. Evidently, catalytic activity of pristine TMC for the processes like hydrogen evolution reaction needs to be improved for them to be considered viable catalysts for practical applications. This can be achieved by the introduction of another element into lattice which causes the formation of heteroatom bonds and the alteration of the average atom–atom bond length.
A theoretical study will be conducted on orthorhombic molybdenum carbide modified by inclusion of Fe, Co, Ni and Cu into its crystalline lattice. Bulk TM-Mo2C will be studied to estimate the changes in the electronic and structural properties of the carbide caused by presence of a dopant metal. Furthermore interaction of (001) TM-Mo2C surfaces with H and H2 will be analyzed in order to acquire information on chemical and catalytic properties of the doped molybdenum carbide and estimate their possible changes caused by varying the location of the dopant metal atom. Obtained theoretical data will be analyzed taking into account available experimental data on TM-Mo2C HER activity

General
The main objective of the present proposal is to determine possible changes in catalytic properties of molybdenum carbide towards hydrogen evolution reaction upon introduction of Fe, Ni, Co and Cu atoms into molybdenum carbide crystalline lattice.


Especificos
– To study theoretically orthorhombic molybdenum carbide surfaces, modified with Fe, Ni, Co and Cu.
– To identify specific adsorption sites available on the TM-Mo2C surfaces, that are not available in unmodified carbide surfaces and compare H and H2 stability on these sites with the stability of the same adsorbates on unmodified Mo2C surfaces.
– To evaluate possible catalytic activity of TM-Mo2C compounds for hydrogen evolution reaction

To our knowledge there are no theoretical studies available on H2 and H interaction with molybdenum carbide modified by insertion of other TM into its crystalline lattice. A systematic analysis of H and H2 adsorption on TM-Mo2C surfaces might help to shed some light on how exactly the presence of dopant metal affects electronic and structural properties of Mo2C in the context of its interaction with hydrogen and bring closer to the understanding of the existing activity trends present in electrochemical systems with different pH. Furthermore, information obtained from a systematic theoretical study of H and H2 interaction with TM-Mo2C could enable design of more efficient materials catalytically active towards HER with predictable properties