Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, P. R. China.
Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming, 650500, P. R. China.
Nat Commun. 2023 Jan 6;14(1):100. doi: 10.1038/s41467-022-35698-0.
Highly dispersed metal sites on the surface of silica, achieved from immobilization of metal precursor within hydroxyl groups, has gained increasing attention in the field of heterogeneous catalyst. However, the special role of adsorbed water derived by hydroxyl groups on the silica is generally ignored. Herein, a new understanding of adsorbed water on the formation of highly dispersed tetrahedral Co(II) (T-cobalt(II)) sites is illustrated. It is indicated that sufficient adsorbed water induces the transformation of precursor of Co(NO) into intermediate of [Co(HO)]. Subsequently, [Co(HO)] makes the highly dispersed T-cobalt(II) sites to be available during direct H-reduction process. A systematic characterization and DFT calculation prove the existence of the adsorbed water and the importance of the intermediate of [Co(HO)], respectively. The as-synthesized catalyst is attempted to the propane dehydrogenation, which shows better reactivity when compared with other reported Co based catalysts.
高度分散的金属位在二氧化硅表面上，通过金属前体在羟基内的固定化来实现，在多相催化剂领域受到越来越多的关注。然而，通常忽略了羟基衍生的吸附水在二氧化硅上的特殊作用。在此，阐述了吸附水在形成高度分散的四面体 Co(II)（T-钴(II)）位中的新作用。结果表明，足够的吸附水诱导 Co(NO)前体转化为[Co(HO)]中间产物。随后，[Co(HO)]在直接 H-还原过程中使得高度分散的 T-钴(II)位变得可用。系统的表征和 DFT 计算分别证明了吸附水的存在和[Co(HO)]中间产物的重要性。所合成的催化剂用于丙烷脱氢反应，与其他报道的 Co 基催化剂相比表现出更好的反应活性。
