Increasing stringent regulations on carbon emissions have favored the development of low carbon emissions technologies as an alternative energy source to fossil fuels. In particular, hydrogen has attracted significant attention of researchers as a clean energy carrier due to its high energy density and low carbon emission. This has led to the development of numerous hydrogen-energy systems. However, the presence of hydrogen in these systems affects the mechanical properties of the structural materials. For instance, steel in most cases suffers from hydrogen embrittlement due to ferrite composition. Therefore, the reduction of hydrogen penetration into the materials is highly desirable. As such, hydrogen permeation barrier deposition has been identified as a promising solution.
There has been some work reported regarding hydrogen permeation barrier films across many fields. Unfortunately, their full potential has not been realized due to several challenges such as variation in the hydrogen-permeation reduction factors that hinder the functionality of barrier materials in practical applications. Recent research work has shown that the barrier performance is dependent on the physical interaction of the barrier’s material and hydrogen. Alternatively, the above-mentioned interaction can be best described using models. However, despite the significant efforts to describe the physical mechanisms underlying hydrogen penetration using the currently available models i.e. composite diffusion model, a mutual conclusion has not been reached. Recently, transition metal carbides especially vanadium carbide and its alloys have exhibited exemplary irradiation performance due to its excellent properties thus a promising candidate for hydrogen permeation barrier coatings.
Recently, a group of researchers: Dr. Yu Liu, Dr. Shaosong Huang, Jianhua Ding, Dr. Yaochun Yang and Dr. Jijun Zhao at the Dalian University of Technology investigated the hydrogen behavior in vanadium carbide based on the density functional calculations. Furthermore, they utilized the transition state theory to analyze hydrogen dissociation, diffusion, and penetration. Their main aim was to predict hydrogen permeation barrier performances in a variety of related materials especially at elevated temperatures. Eventually, they compared the results obtained through density functional calculations to those existing in literature taking into account the quantum correction effects.
From the experimental results, the authors observed that the dissociation of hydrogen was highly favored by the closeness of hydrogen to the surface. However, the temperature-controlled activation energy barrier highly influenced hydrogen dissociation at the surface. Consequently, this was attributed to the resistant effects of hydrogen atom permeation at the surface.
In summary, the calculated results were consistent with those available in the literature thus confirming the feasibility of the simulation in predicting the hydrogen behavior in materials both at low and elevated temperatures. Altogether, based on the good hydrogen permeation barrier performance, vanadium carbide is a promising candidate for use as hydrogen permeation barrier which will lead to the realization of the related applications such as enhancing the use of hydrogen as an alternative to fossil fuel. Their research work is currently published in International Journal of Hydrogen Energy.
Liu, Y., Huang, S., Ding, J., Yang, Y., & Zhao, J. (2019). Vanadium carbide coating as hydrogen permeation barrier: A DFT study. International Journal of Hydrogen Energy, 44(12), 6093-6102.Go To International Journal of Hydrogen Energy