Active Site Formation for Oxygen Reduction Reaction on Carbon-Support-Free Titanium Oxynitride with Boosted Activity in Acidic Media
Active Site Formation for Oxygen Reduction Reaction on Carbon-Support-Free Titanium Oxynitride with Boosted Activity in Acidic Media
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DOI：
10.1021/acsaem.7b00100
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发表时间：
2018-01-01
影响因子：
6.4
通讯作者：
Hattori, Yuhei
中科院分区：
文献类型：
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作者：
Chisaka, Mitsuharu;Yamamoto, Yusuke;Hattori, Yuhei
研究了最近报道的无碳负载的氮氧化钛（TiOxNy）催化剂的活性中心形成过程，以揭示在酸性介质中提高氧还原反应（ORR）活性的关键因素。钛源和导电氧化物载体的存在都不是显示活性的关键，而氧化的TiN表面被揭示是必要的。在不使用碳载体的情况下，主要通过优化前体分散体中的盐酸浓度以增加表面氮含量，在0.1 mol dm（-3）H2SO 4溶液中成功地将ORR活性提高到最佳碳负载氧化物基催化剂（多壁碳纳米管上的氮氧化锆）的水平。催化剂是稳定的;即，在0.6 - 1.0V（相对于可逆氢电极）电压范围内，经过20000次电位循环后，活性保持不变。
An active site formation process for recently reported carbon-support-free titanium oxynitride (TiOxNy) catalysts is investigated to reveal the critical factors for enhancing the oxygen reduction reaction (ORR) activity in acidic media. Neither the titanium source nor the presence of a conductive oxide support is a key to displaying activity whereas an oxidized TiN surface is revealed to be necessary. The ORR activity is successfully enhanced without using a carbon support to the level of the best carbon-supported oxide-based catalyst, zirconium oxynitride on multiwalled carbon nanotube in 0.1 mol dm(-3) H2SO4 solution, mainly by optimizing hydrochloric acid concentration in the precursor dispersion to increase the surface nitrogen content. The catalyst is stable; i.e., the activity remained unchanged after 20 000 potential cycles between 0.6 and 1.0 V versus reversible hydrogen electrode.