Instituto de Tecnología Química (UPV-CSIC), Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Avenida de los Naranjos s/n, 46022 Valencia, Spain.
Phys Chem Chem Phys. 2011 Feb 21;13(7):2603-12. doi: 10.1039/c0cp01996h. Epub 2011 Jan 19.
The activity and selectivity towards carbonylation presented by Brønsted acid sites located inside the 8MR pockets or in the main 12MR channels of mordenite is studied by means of quantum-chemical calculations, and the mechanistic differences between methanol and DME carbonylation are investigated. The selectivity towards carbonylation is higher inside the 8MR pockets, where the competitive formation of DME and hydrocarbons that finally leads to catalyst deactivation is sterically impeded. Moreover, inclusion of dispersion interactions in the calculations leads to agreement between the calculated activation barriers for the rate determining step and the experimentally observed higher reactivity of methoxy groups located inside the 8MR channels.
通过量子化学计算研究了位于丝光沸石的 8MR 口袋内部或主要 12MR 通道中的 Brønsted 酸位对羰基化反应的活性和选择性，并研究了甲醇和 DME 羰基化反应的机理差异。在 8MR 口袋内部，羰基化反应的选择性更高，因为那里竞争形成的 DME 和烃类最终会导致催化剂失活，受到空间位阻的阻碍。此外，在计算中包含色散相互作用，使得计算得出的速率决定步骤的活化能垒与实验观察到的位于 8MR 通道内的甲氧基基团的更高反应性之间达成一致。
