Ammonia represents a promising liquid fuel for hydrogen storage, but its large-scale application is limited by the need for precious metal ruthenium (Ru) as catalyst. Here we report on highly efficient ammonia decomposition using novel high-entropy alloy (HEA) catalysts made of earth abundant elements. Quinary CoMoFeNiCu nanoparticles are synthesized in a single solid-solution phase with robust control over the Co/Mo atomic ratio, including those ratios considered to be immiscible according to the Co-Mo bimetallic phase diagram. These HEA nanoparticles demonstrate substantially enhanced catalytic activity and stability for ammonia decomposition, with improvement factors achieving >20 versus Ru catalysts. Catalytic activity of HEA nanoparticles is robustly tunable by varying the Co/Mo ratio, allowing for the optimization of surface property to maximize the reactivity under different reaction conditions. Our work highlights the great potential of HEAs for catalyzing chemical transformation and energy conversion reactions.

氨是一种有前途的储氢液体燃料，但由于需要贵金属钌（Ru）作为催化剂，氨的大规模应用受到了限制。在这里，我们报道了使用由富含地球的元素制成的新型高熵合金（HEA）催化剂进行的高效氨分解。在单一固溶体相中合成了Quaryary CoMoFeNiCu纳米粒子，并具有对Co / Mo原子比（包括根据Co-Mo双金属相图认为不混溶的那些比）的稳健控制。这些HEA纳米颗粒表现出显着增强的氨分解催化活性和稳定性，与Ru催化剂相比，改进因子可达到> 20。通过改变Co / Mo比，可以稳定地调节HEA纳米颗粒的催化活性，允许优化表面性质，以在不同反应条件下最大化反应性。我们的工作凸显了HEA在催化化学转化和能量转化反应方面的巨大潜力。