Selective Catalytic Reduction at Quasi-Perfect Pt(100) Domains: A Universal Low-Temperature Pathway from Nitrite to N2
Selective Catalytic Reduction at Quasi-Perfect Pt(100) Domains: A Universal Low-Temperature Pathway from Nitrite to N2
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DOI：
10.1021/ja203234v
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发表时间：
2011-07-20
影响因子：
15
通讯作者：
Koper, Marc T. M.
中科院分区：
文献类型：
--
作者：
Duca, Matteo;Figueiredo, Marta C.;Koper, Marc T. M.
研究了碱性介质中亚硝酸根在准完美铂(100)电极上高选择性转化为N-2的反应，重点考察了其结构敏感性及其反应机理。需要高质量的(100)平台来优化催化活性和引导N-2的选择性：任何对称性的缺陷都会显著减少[(100)x(110)]和[(100)x(111)]表面的N-2析出。另一方面，亚硝酸盐还原被证明是(100)表面独特的内在能力的另一个例子，它催化涉及键断裂和连续键形成的反应。在目前的情况下，(100)能够将亚硝酸盐还原为NH2(ADS)，在一定的势窗内与NOADS结合，在Langmuir-HinShelwood反应中得到N-2。我们的发现与其他生成N-2的过程相似，从细菌缺氧氨氧化(Anammox)到在超高真空条件下在铂(100)晶体上的高温NO+NH3反应，因此这两个含氮物种的结合是生成N-2的普遍(低温)途径。指出了该途径与其他N-2生成途径相比的优点。
The highly selective conversion of nitrite to N-2 at a quasi-perfect Pt(100) electrode in alkaline media was investigated with a particular emphasis on its structure sensitivity and its mechanism. High-quality (100) terraces are required to optimize the catalytic activity and steer the selectivity to N-2: defects of any symmetry dramatically reduce the N-2 evolution at [(100) x (110)] and [(100) x (111)] surfaces. On the other hand, nitrite reduction proves to be an additional example of the unique intrinsic ability of (100) surfaces to catalyze reactions involving bond breaking and successive bond formation. In the present case, (100) is able to reduce nitrite to NH2,(ads) which in a certain potential window combines with NOads to give N-2 in a Langmuir-Hinshelwood reaction. Our findings are similar to those for other processes generating N-2, from bacterial anoxic ammonia oxidation ("anammox") to the high-temperature NO + NH3 reaction at Pt(100) crystals under ultra-high-vacuum conditions, thus suggesting that the combination of these two nitrogen-containing species is a universal (low-temperature) pathway to N-2. The advantages of this pathway over other N-2-generating pathways are pointed out.