Constructing well-defined heterostructure interfaces in catalysts is an efficient strategy to break the so-called scaling relationships and to accelerate the reactions involving multiple intermediates. Here a cluster–cluster heterostructure catalyst composed of crystalline ruthenium cluster and amorphous chromium oxide cluster is designed to realize high-performance alkaline hydrogen electrocatalysis. The strongly coupled cluster–cluster heterostructure interface induces a unique interfacial interpenetration effect, which simultaneously optimizes the adsorption of intermediates on each cluster. The resulting catalyst exhibits impressive catalytic activities for the hydrogen oxidation reaction (exchange current density of 2.8 A mg⁻¹_Ru) and the hydrogen evolution reaction (mass activity of 23.0 A mg⁻¹_Ru at the overpotential of 100 mV) in alkaline media. The hydroxide exchange membrane fuel cell delivers a mass activity of 22.4 A mg⁻¹_Ru at 0.65 V and outstanding durability with no voltage loss over 105 h operation at 500 mA cm⁻². The present work demonstrates the superiority of cluster–cluster heterostructure interface towards the development of advanced catalysts.

在催化剂中构建明确的异质结构界面是打破所谓的尺度关系并加速涉及多个中间体的反应的有效策略。本文设计了一种由晶态钌簇和非晶态氧化铬簇组成的簇-簇异质结构催化剂，以实现高性能碱性氢电催化。强耦合的簇-簇异质结构界面引起独特的界面互穿效应，同时优化了每个簇上中间体的吸附。所得催化剂在碱性介质中对氢氧化反应（交换电流密度为2.8 A mg ^-1 _Ru）和析氢反应（过电势为100 mV时质量活性为23.0 A mg ^-1 _Ru）表现出令人印象深刻的催化活性。氢氧化物交换膜燃料电池在0.65 V下的质量活性为22.4 A mg ^-1 _Ru，并且具有出色的耐用性，在500 mA cm ^-2下运行105小时内没有电压损失。目前的工作证明了簇-簇异质结构界面在开发先进催化剂方面的优越性。