Modification of the hydrogen compression properties of Zr–Fe–Cr–V-based alloys through Ti doping

Hydrogen refueling stations typically rely on compressors to increase the pressure of hydrogen received from long-tube trailers, enabling efficient refill of hydrogen storage tanks. However, mechanical hydrogen compressors are unable to effectively harness residual hydrogen below 6 MPa in long-tube trailers. Herein, we developed a ZrFe2-based hydrogen compression alloy to enhance the hydrogen pressure that meets the input pressure requirement of mechanical hydrogen compressors. Specifically, the co-substitution of Cr and V for Fe was conducted to reduce the plateau slope and hysteresis, and Ti was introduced to partially substitute Zr to regulate the plateau pressure. The effects of Ti on the structure and hydrogen storage properties of Zr–Fe–Cr-based alloys have been investigated by first-principles calculations, wherein Zr1-xTixFe1.7Cr0.2V0.1 (x = 0, 0.1, 0.2, 0.3, 0.4) alloys were designed and synthesized. The optimized Zr0.8Ti0.2Fe1.7Cr0.2V0.1 alloy provided a hydrogen absorption capacity of 1.22 wt% under 3.88 MPa H2 pressure at 300 K and achieved an effective hydrogen compression capacity of 1.07 wt% at 355 K at an H2 desorption pressure of 6.36 MPa. This advancement holds great promise for the efficient utilization of residual hydrogen at approximately 6 MPa in long-tube trailers, thus leading to a significant improvement in hydrogen transportation efficiency.