Supplementary information files for "Quantum confinement-induced anti-electrooxidation of metallic nickel electrocatalysts for hydrogen oxidation"

Supplementary files for article "Quantum confinement-induced anti-electrooxidation of metallic nickel electrocatalysts for hydrogen oxidation"The anion-exchange-membrane fuel cell (AEMFC) is an attractive and cost-effective energy-conversion technology because it can use Earth-abundant and low-cost non-precious metal catalysts. However, non-precious metals used in AEMFCs to catalyse the hydrogen oxidation reaction are prone to self-oxidation, resulting in irreversible failure. Here we show a quantum well-like catalytic structure (QWCS), constructed by atomically confining Ni nanoparticles within a carbon-doped-MoOx/MoOx heterojunction (C-MoOx/MoOx) that can selectively transfer external electrons from the hydrogen oxidation reaction while remaining itself metallic. Electrons of Ni nanoparticles gain a barrier of 1.11 eV provided by the QWCS leading to Ni stability up to 1.2 V versus the reversible hydrogen electrode (VRHE) whereas electrons released from the hydrogen oxidation reaction easily cross the barrier by a gating operation of QWCS upon hydrogen adsorption. The QWCS-catalysed AEMFC achieved a high-power density of 486 mW mgNi−1 and withstood hydrogen starvation operations during shutdown–start cycles, whereas a counterpart AEMFC without QWCS failed in a single cycle.© The Author(s), CC BY 4.0

论文《量子限域诱导金属镍电催化剂抗电氧化用于氢氧化反应》的补充材料
阴离子交换膜燃料电池（anion-exchange-membrane fuel cell, AEMFC）是一类极具吸引力且成本效益优异的能量转换技术，因其可使用地壳储量丰富、成本低廉的非贵金属催化剂。然而，用于AEMFC中催化氢氧化反应的非贵金属极易发生自氧化，进而导致器件不可逆失效。本文报道了一种类量子阱催化结构（quantum well-like catalytic structure, QWCS）：通过将Ni纳米颗粒原子级限域于碳掺杂MoOx/MoOx异质结（carbon-doped-MoOx/MoOx, C-MoOx/MoOx）中，该结构可选择性地转移氢氧化反应产生的外部电子，同时自身保持金属态。Ni纳米颗粒的电子获得了QWCS提供的1.11 eV势垒，使得Ni在相对于可逆氢电极（reversible hydrogen electrode, RHE）的电位达1.2 V（VRHE）时仍保持稳定；而氢氧化反应释放的电子可在氢吸附时通过QWCS的门控操作轻松跨越该势垒。搭载QWCS的AEMFC实现了486 mW·mg⁻¹_Ni的高功率密度，且可在停机-启动循环过程中耐受氢饥饿工况；而未搭载QWCS的对照AEMFC仅在单个循环内即发生失效。© 作者，CC BY 4.0