Effect of Cold Rolling on the Hydrogen Desorption Behavior of Binary Metal Hydride Powders under Microwave Irradiation

Ivaldete da Silva Dupim,Sydney Ferreira Santos,Jacques Huot

doi:10.3390/met5042021

Ivaldete da Silva Dupim, Sydney Ferreira Santos + Show 1 more

Open Access

https://doi.org/10.3390/met5042021

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Abstract

In this paper we report that cold rolling could drastically improve hydrogen desorption kinetics under microwave irradiation. Samples of metal hydride powders (TiH2, ZrH2, and MgH2) in as-received conditions and after cold rolling were microwave irradiated in a vacuum using a simple experimental setup. After irradiation, the samples were characterized by X-ray diffraction in other to evaluate the effectiveness of microwave heating. The diffraction patterns indicated that only MgH2 could be fully decomposed (dehydrided) in the as received state. TiH2 was only partially decomposed while no decomposition was observed for ZrH2. However, cold rolling the hydride powders prior to microwave heating led to a significant improvement of hydride decomposition, resulting in the complete dehydriding of TiH2 and extensive dehydriding of ZrH2. These results clearly indicated the positive effects of cold rolling on the microwave assisted desorption of the investigated binary hydrides.

Highlights

The use of microwave energy in material synthesis and processing has been widely investigated over the years
The strong particle size refinement promoted by cold rolling on the hydride powders can be clearly seen
The particle size refinement is a positive feature for microwave heating since the microwave penetration depth in metals is small

Summary

Introduction

The use of microwave energy in material synthesis and processing has been widely investigated over the years. This reaction is complex, presenting possible alternative pathways and side reactions with atmosphere or container material contaminations These authors reported success in producing single phase Li4NH by microwave synthesis over a much shorter period of time than necessary for conventional heating methods. Nakamori et al [27] investigated the effect of microwave irradiation on some metal hydrides and complex hydrides These authors reported that some of the investigated transition metal hydrides presented small hydrogen desorption (TiH2 and VH0.81), as indicated by shifts in diffraction peaks positions of the hydride phases, whereas others did not indicate any hydrogen release (ZrH2 and LaH2.48). We investigate the effect of cold rolling on the hydrogen desorption behavior of binary hydride powders during microwave irradiation. This investigation was motivated by the reports concerning the positive effects of cold rolling on the hydrogen desorption kinetics in several hydride systems under conventional heating [31,32,33,34,35,36] and the lack of investigations focusing the effect of cold rolling on the hydrogen desorption of hydrides during microwave heating

Experimental Section

Electron Microscopy

X-ray Diffraction

Conclusions