Effect of Cr addition on the structure and hydrogen storage properties of TVZrNb high entropy alloy

• Grant number: 19/17081-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2019
• End date: April 30, 2021
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Guilherme Zepon
• Grantee: André Gonçalves de Pontes
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 13/05987-8 - Processing and characterization of amorphous, metastable and nano-structured metallic alloys, AP.TEM

Abstract

Hydrogen is considered the ideal energy vector to explore the benefits of renewable sources, such as wind, solar and hydro. However, safe, reliable, efficient and cost-effective storage and transport of hydrogen is still a scientific and technological challenge that must be overcome. In recent years, high entropy alloys with promising hydrogen storage properties have been reported. In a recent publication, it was verified that TiVNbCr alloy is able to be hydrogenated without any previous activation treatment and presenting low hydrogen desorption temperatures evaluated by DSC (Tonset = 180 ° C). Beyond that, this alloy was capable of being cycled at room temperature (at 20 bar H2 for hydrogenation and permanent vacuum for desorption) without losing capacity. The hypothesis of this project is that the key to control the hydrogen storage properties, which means the desorption temperature and low-temperature cyclability, is the composition control by balancing the content of hydride forming elements, such as Mg, Ti, V, Zr, Nb, Hf, and Ta, with the content of non-hydride forming elements, such as Cr, Fe, Co, Ni, etc. Therefore, this research project aims to study the effect of the addition of Cr in the structure and hydrogen storage properties of TiVZrNb alloy.