Saiz Fernan, Bernasconi Leonardo
Institut de Ciència de Materials de Barcelona (ICMAB), Spanish National Research Council (CSIC), Campus de la UAB, Bellaterra, 08193, Spain.
Phys Chem Chem Phys. 2020 Jun 14;22(22):12821-12830. doi: 10.1039/d0cp01285h. Epub 2020 May 29.
We study the reactivity of Fe(iv)O moieties supported by a metal-organic framework (MOF-74) in the oxidation reaction of methane to methanol using all-electron, periodic density-functional theory calculations. We compare results concerning the electronic properties and reactivity obtained using two hybrid (B3LYP and sc-BLYP) and two standard generalised gradient corrected (PBE and BLYP) semi-local density functional approximations. The semi-local functionals are unable to reproduce the expected reaction profiles and yield a qualitatively incorrect representation of the reactivity. Non-local hybrid functionals provide a substantially more reliable description and predict relatively modest (ca. 60 kJ mol) reaction energy barriers for the H-atom abstraction reaction from CH molecules. We examine the origin of these differences and we highlight potential means to overcome the limitations of standard semi-local functionals in reactivity calculations in solid-state systems.
我们使用全电子周期性密度泛函理论计算方法，研究了金属有机框架（MOF - 74）负载的Fe(iv)O部分在甲烷氧化为甲醇反应中的反应活性。我们比较了使用两种杂化（B3LYP和sc - BLYP）以及两种标准广义梯度校正（PBE和BLYP）半局域密度泛函近似所获得的关于电子性质和反应活性的结果。半局域泛函无法重现预期的反应轮廓，并且对反应活性给出了定性错误的描述。非局域杂化泛函提供了实质上更可靠的描述，并预测从CH分子中提取H原子的反应能量垒相对适中（约60 kJ/mol）。我们研究了这些差异的来源，并强调了克服固态系统反应活性计算中标准半局域泛函局限性的潜在方法。
