Hollow cobalt phosphide octahedral pre-catalysts with exceptionally high intrinsic catalytic activity for electro-oxidation of water and methanol
Hollow cobalt phosphide octahedral pre-catalysts with exceptionally high intrinsic catalytic activity for electro-oxidation of water and methanol
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DOI：
10.1039/c8ta07958g
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发表时间：
2018-10
影响因子：
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通讯作者：
Junyuan Xu;Yuefeng Liu;Junjie Li;Isilda Amorim;Bingsen Zhang;D. Xiong;Nan Zhang;S. Thalluri
中科院分区：
文献类型：
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作者：
Junyuan Xu;Yuefeng Liu;Junjie Li;Isilda Amorim;Bingsen Zhang;D. Xiong;Nan Zhang;S. Thalluri
微结构工程是提高催化剂电催化活性的有效途径。形状控制的中空纳米结构代表了一类用于电催化的有趣结构，因为它们可以提供大的表面积，优选暴露的活性位点，减少电荷和质量传输的扩散路径，以及由于纳米腔效应而增强的催化活性。在此，我们首次报道了通过多步反应合成具有明确八面体形状的空心磷化钴纳米颗粒（CoP OCHs）。当用作碱性溶液中析氧反应（OER）的预催化剂时，所获得的CoP OCH不仅表现出高表观催化活性，只需240 mV的过电势即可提供10 mA cm−2的基准电流密度，而且还表现出极高的基于催化剂表面积的周转频率（TOF）为17.6 s−1和基于催化剂质量的TOF为0.072 s−1 在 300 mV 的低过电势下表现出优异的内在催化活性。此外，CoP OCHs还对甲醇氧化反应（MOR）表现出高电催化活性，优于迄今为止报道的大多数基于金属磷化物的MOR催化剂。这里报道的合成策略可以很容易地扩展到制备其他中空形状控制的金属磷化物催化剂。
Microstructural engineering is an effective approach to improving electrocatalytic activity of a catalyst. Shape-controlled hollow nanostructures represent a class of interesting architectures for use in electrocatalysis, given that they may offer large surface area, preferably exposed active sites, reduced diffusion pathways for both charge and mass transport, as well as enhanced catalytic activity due to the nano-cavity effect. Herein, we for the first time report the synthesis of hollow cobalt phosphide nanoparticles with a well-defined octahedral shape (CoP OCHs) via multi-step reactions. When used as pre-catalysts for the oxygen evolution reaction (OER) in an alkaline solution, the as-obtained CoP OCHs not only show high apparent catalytic activity requiring an overpotential of only 240 mV to deliver the benchmark current density of 10 mA cm−2, but also exhibit an exceptionally high catalyst surface-area-based turnover frequency (TOF) of 17.6 s−1 and a catalyst mass-based TOF of 0.072 s−1 at a low overpotential of 300 mV, demonstrating excellent intrinsic catalytic activity. Moreover, the CoP OCHs also show high electrocatalytic activity for the methanol oxidation reaction (MOR), outperforming most metal phosphide based MOR catalysts reported so far. The synthetic strategy reported here can be readily extended to prepare other hollow shape-controlled metal phosphide catalysts.