Transforming Acidic Corrosion and Embrittlement into a Hydrogen-Trapping Cage

TL;DR

This paper introduces a novel method to engineer hydrogen-trapping microstructures in metals by converting corrosion and embrittlement processes into a constructive design, enabling efficient hydrogen storage and catalytic conversion under mild conditions.

Contribution

It presents a new materials design strategy that transforms degradation mechanisms into a platform for synthesizing and stabilizing metal hydrides, including challenging targets like LiH and NaH.

Findings

Successfully synthesized over 20 hydrides, including LiH and NaH.

Developed a titanium hydride electrocatalyst with high current density for nitrate reduction.

Demonstrated in-situ hydrogen trapping and stabilization in metals under mild conditions.

Abstract

The vision of a hydrogen economy demands efficient platforms to close the gap between sustainable proton sources and solid-state hydrogen carriers. Metal hydrides serve as key carriers, yet their synthesis remains constrained by the energy-intensive use of high-pressure H2, which fragments the hydrogen chain. Here, we overturn this paradigm by transforming two classic degradation mechanisms, acidic corrosion and hydrogen embrittlement, into a constructive materials-design strategy. We demonstrate that synergistic control of these processes in acid enables the in-situ engineering of a "hydrogen-trapping cage" (HTC) microstructure within metals. Composed of a dense defect network, this cage directly captures and stabilizes protons as hydrides under mild conditions, guided by the universal criterion |DeltaPeq| > DeltaPph. Using this platform, we synthesize over 20 hydrides, including challenging targets such as LiH and NaH, and showcase its functional power with a cage-rich titanium hydride electrocatalyst. This catalyst achieves an exceptional current density of 1.07 A cm-2 for nitrate-to-ammonia conversion, attributed to rapid H- transport within the engineered cage. This work establishes a transformative "failure-to-function" paradigm, delivering an integrated platform that unifies hydrogen capture, stabilization, and conversion.