Effect of surface morphology on initial hydrogen diffusion in vanadium alloys

Abstract

The hydrogen absorption properties and diffusion behavior in V-3A alloys (V, V97Al3, V97Ru3) were studied by pressure-composition-temperature measurements and first-principles calculations. It was found that addition of Al and Ru could increase first plateau pressure. With the largest surface area among these alloy powders, V-3Ru achieved the highest hydrogen diffusivity at 433 K under an initial pressure of 1500 Pa. Hydrogen diffusion behaviors were examined by DFT calculations of barriers in both surface and internal cases of V-3A alloys. It revealed that initial diffusion rate was related to surface morphology. The results are expected to provide useful guidelines for understanding hydrogen absorption and diffusion properties of hydrogen storage materials.