Electrocatalytic oxidation of ammonia on Pt: Mechanistic insights into the formation of N2 in alkaline media
Electrocatalytic oxidation of ammonia on Pt: Mechanistic insights into the formation of N2 in alkaline media
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Pt 上氨的电催化氧化：碱性介质中 N2 形成的机理见解
DOI：
10.1016/j.jcat.2021.10.029
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发表时间：
2021-10
影响因子：
7.3
通讯作者：
Bo Yang
中科院分区：
文献类型：
--
作者：
Kunran Yang;Jian Liu;Bo Yang
电化学氨氧化反应(AOR)是利用氨的最有效方法之一。目前，AOR过程中的有利偶联过程和最重要的中间体仍在争论中。在这里，我们使用从头算分子动力学(AIMD)方法，结合特意设计的自由能计算，深入研究了AOR过程中基本步骤的能量学。在AOR过程中，N2生成的主要途径是NH3脱氢为NH2，随后NH2+与NH2偶联生成N2H4，然后N2H4逐步脱氢为N2H4。在这一过程中，格利舍尔-毛雷尔机制被发现是受青睐的。确定了NH3脱氢为NH2的限速步骤，而NH2是最重要的中间体。通过这项工作，揭示了AOR的整体反应网络和相应的能量，这可能会启发对AOR的理解，并进一步加速相应的催化剂创新。
Electrochemical ammonia oxidation reaction (AOR) is one of the most effective methods to utilize ammonia. Currently, the favorable coupling process during AOR and most important intermediates are still under debate. Herein we usedab initiomolecular dynamics (AIMD) method combined with deliberately designed free-energy calculations to thoroughly study the energetics of elementary steps during AOR. The main pathway of N2formation during AOR is initiated by the dehydrogenation of NH3to NH2, and subsequent NH2+ NH2coupling to form N2H4, followed by stepwise dehydrogenation of N2H4to N2. The Gerischer-Mauerer mechanism was found to be favored in the process. The dehydrogenation of NH3to NH2was determined to be the rate-limiting step, and NH2is the most important intermediate. Through this work, the overall reaction network and corresponding energetics of AOR is revealed, which may enlighten the understanding of AOR and further accelerate corresponding catalyst innovation.