University of Wisconsin-Madison, Department of Chemistry, 1101 University Avenue, 53706 Madison, WI (USA).
Université de Lyon, CNRS, Ecole Normale Supérieure de Lyon, Laboratoire de Chimie, 46 Allée d'Italie, F-69342 Lyon Cedex 07 (France).
Angew Chem Int Ed Engl. 2015 Jun 26;54(27):7799-804. doi: 10.1002/anie.201501942. Epub 2015 May 12.
Copper-exchanged SSZ-13 is a very efficient material in the selective catalytic reduction of NO(x) using ammonia (deNO(x)-SCR) and characterizing the underlying distribution of copper sites in the material is of prime importance to understand its activity. The IR spectrum of NO adsorbed to divalent copper sites are modeled using ab initio molecular dynamics simulations. For most sites, complex multi-peak spectra induced by the thermal motion of the cation as well as the adsorbate are found. A finite temperature spectrum for a specific catalyst was constructed, which shows excellent agreement with previously reported data. Additionally these findings allow active and inactive species in deNO(x)-SCR to be identified. To the best of our knowledge, this is the first time such complex spectra for single molecules adsorbed to single active centers have been reported in heterogeneous catalysis, and we expect similar effects to be important in a large number of systems with mobile active centers.
铜交换 SSZ-13 是一种非常有效的材料，可用于使用氨选择性催化还原 NO(x)（deNO(x)-SCR），并且表征材料中铜位的基础分布对于理解其活性至关重要。使用从头算分子动力学模拟对吸附在二价铜位上的 NO 的红外光谱进行建模。对于大多数位，发现由于阳离子和吸附物的热运动引起的复杂多峰光谱。为特定催化剂构建了有限温度光谱，该光谱与先前报道的数据吻合得非常好。此外，这些发现还允许识别 deNO(x)-SCR 中的活性和非活性物质。据我们所知，这是首次在多相催化中报道吸附在单个活性中心上的单个分子的这种复杂光谱，我们预计在具有可移动活性中心的大量体系中，类似的效应将非常重要。
