Probing the Crystal and Electronic Structures of Molybdenum Oxide in Redox Process: Implications for Energy Applications
Probing the Crystal and Electronic Structures of Molybdenum Oxide in Redox Process: Implications for Energy Applications
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DOI：
10.1021/acsaem.9b01747
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发表时间：
2019-10
影响因子：
6.4
通讯作者：
Huayu Peng;Weiwei Meng;He Zheng;Yanjie Wei;H. Sheng;Huihui Liu;Lei Li;Guangyu Wen;
中科院分区：
文献类型：
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作者：
Huayu Peng;Weiwei Meng;He Zheng;Yanjie Wei;H. Sheng;Huihui Liu;Lei Li;Guangyu Wen;
有关氧化还原反应过程中钼 (Mo) 及其氧化物的相和价态演化的知识对于推进其能源应用（例如电催化）至关重要，但不幸的是，这在很大程度上尚未得到探索。本文在非原位和原位实验相结合的基础上，研究了原子和电子结构对Mo/氧化物核壳结构电催化性能的影响。首先，揭示了纳米级 Mo 氧化过程中的两步反应途径：形成无定形 MoO3 (A-MoO3) 壳，然后形成结晶 α-MoO3 成核。结果表明，A-MoO3 的电催化性能优于 α-MoO3，这主要是由于前者材料具有更多的催化活性位点。此外，原位透射电子显微镜观察表明，A-MoO3壳在还原环境下可以快速还原成金属MoO2，这很可能发生在析氢过程中......
Knowledge regarding the phase and valence state evolution of molybdenum (Mo) and its oxides during the redox reaction is essential for advancing their energy applications (e.g., electrocatalysis), which unfortunately remains largely unexplored. Herein, the effects of atomic and electronic structures on the electrocatalytic performance of Mo/oxides core–shell structures are investigated on the basis of the combination of ex situ and in situ experiments. First, a two-step reaction pathway is revealed during the oxidation of nanoscale Mo: the formation of amorphous MoO3 (A-MoO3) shells followed by the nucleation of crystalline α-MoO3. It is shown that the electrocatalytic performance of A-MoO3 is superior to that of α-MoO3, mainly due to more catalytically active sites in the former material. Furthermore, in situ transmission electron microscopy observations show that the A-MoO3 shell can be rapidly reduced into metallic MoO2 under reductive environment, which is likely to occur during the hydrogen evolution...