Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China.
Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China.
Molecules. 2023 Jan 19;28(3):1037. doi: 10.3390/molecules28031037.
The characteristics of active sites on the surface of albite were theoretically analyzed by density functional theory, and the activation of the C-H bond of methane using an albite catalyst and the reaction mechanism of preparing C hydrocarbons by nonoxidative coupling were studied. There are two frustrated Lewis pairs (FLPs) on the (001) and (010) surfaces of albite; they can dissociate H under mild conditions and show high activity for the activation of methane C-H bonds. CH molecules can undergo direct dissociative adsorption on the (010) surface, whereas a 50.07 kJ/mol activation barrier is needed on the (001) surface. The prepared albite catalyst has a double combination function of the (001) and (010) surfaces; these surfaces produce a spillover phenomenon in the process of CH activation reactions, where CH overflows from the (001) surface with CH adsorbed on the (010) surface to achieve nonoxidative high efficiently C-C coupling with an activation energy of 18.51 kJ/mol. At the same time, this spillover phenomenon inhibits deep dehydrogenation, which is conducive to the selectivity of the C hydrocarbons. The experimental results confirm that the selectivity of the C hydrocarbons is maintained above 99% in the temperature range of 873 K to 1173 K.
通过密度泛函理论对钠长石表面活性位的特征进行了理论分析，并研究了钠长石催化剂上甲烷 C-H 键的活化和非氧化偶联制备 C 烃的反应机理。钠长石的（001）和（010）表面上存在两个受阻路易斯对（FLP）；它们可以在温和条件下解离 H，并显示出对甲烷 C-H 键活化的高活性。CH 分子可以在（010）表面上进行直接解离吸附，而在（001）表面上则需要 50.07 kJ/mol 的活化能。所制备的钠长石催化剂具有（001）和（010）表面的双重组合功能；这些表面在 CH 活化反应过程中产生了溢出现象，其中 CH 从（001）表面溢出，而在（010）表面上吸附的 CH 与（001）表面上吸附的 CH 发生非氧化高效 C-C 偶联，其活化能为 18.51 kJ/mol。同时，这种溢出现象抑制了深度脱氢，有利于 C 烃的选择性。实验结果证实，在 873 K 至 1173 K 的温度范围内，C 烃的选择性保持在 99%以上。
