Metal organic frameworks (MOFs) containing zirconium secondary building units (SBUs) in UiO‐67 and related MOFs, are highly active for neutralizing both the chemical warfare agents and simulants, such as dimethyl methylphosphonate (DMMP). However, two recent publications gave conflicting reports of DMMP reaction with UiO‐67 under ultra high vacuum (UHV) conditions, with one reporting chemisorption and reaction (Wang et al., J Phys Chem C, 2017, 121, 11261–11272) and the other reporting only physisorption and reversible desorption (Ruffley et al., J Phys Chem C, 2019, 123, 19748–19758) from very similar temperature programmed desorption experiments. We show that the discrepancy between these experiments may be explained by different levels of missing linker defects in the UiO‐67 samples. We present density functional theory calculations showing that SBU sites having two‐adjacent missing linkers exhibit reaction barriers that are about 30 kJ/mol lower than SBU sites having a single missing linker. We also show that topology of the undercoordinated sites plays an important role in the reaction barrier under UHV conditions.

中文翻译：

---

缺陷对基于Zr的金属有机骨架中化学战剂模拟物分解的影响

在UiO-67和相关MOF中包含锆二级建筑单元（SBU）的金属有机框架（MOF）对中和化学战剂和模拟物（例如甲基膦酸二甲酯（DMMP））具有很高的活性。但是，最近的两篇出版物给出了在超高真空（UHV）条件下DMMP与UiO-67反应的报道相互矛盾，其中一份报道了化学吸附和化学反应（Wang等，J Phys Chem C，2017，121，11261-11272）和另一类仅报道了非常相似的程序升温脱附实验的物理吸附和可逆脱附（Ruffley等人，J Phys Chem C，2019，123，19748–19758）。我们表明，这些实验之间的差异可以用UiO-67样品中不同水平的接头缺陷缺失来解释。我们提出的密度泛函理论计算表明，具有两个相邻缺失接头的SBU位点的反应势垒比具有单个缺失接头的SBU位点低约30 kJ / mol。我们还表明，配位不足的拓扑在特高压条件下的反应屏障中起着重要作用。