Huang Zijun, He Dedong, Lu Jichang, Han Lanfang, Li Kongzhai, Chen Dingkai, Cao Xiaohua, Li Tan, Luo Yongming
Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming, 650500, China.
Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, China.
Angew Chem Int Ed Engl. 2024 Sep 2;63(36):e202408391. doi: 10.1002/anie.202408391. Epub 2024 Aug 2.
The electronic structure of active metal centers plays an indispensable role in regulating catalytic reactivity in heterogeneous catalysis, developing other metals as promoters to decorate electronic state is a common strategy, while non-metal component of carbon as electronic additives to regulate d-band center has rarely been studied in thermal-catalysis field. Herein, we report electron-deficient tetrahedral Co(II) (T-cobalt(II)) centers through carbon-layer modulation for propane dehydrogenation (PDH). It is indicated that bifunctional sites of both T-cobalt(II) and metallic-cobalt are designed, and the in situ generated carbon through the disproportionation of CO on metallic-cobalt can cover the inactive metallic-cobalt and tailor d-band of active T-cobalt(II) simultaneously. More importantly, the pre-deposited carbon-layer is proposed to decrease electron density of T-cobalt(II) and make d-band center closer to Fermi level, consequently promotes C-H activation in PDH reaction. This study provides new perspective for the utilization of inactive carbon as electronic promoters and unlocks new opportunity to fabricate efficient PDH and other heterogeneous catalysts.
活性金属中心的电子结构在多相催化中调节催化反应活性方面起着不可或缺的作用，开发其他金属作为促进剂来修饰电子态是一种常见策略，而在热催化领域，将碳的非金属成分作为电子添加剂来调节d带中心的研究却很少。在此，我们报道了通过碳层调制实现缺电子四面体Co(II)（T-钴(II)）中心用于丙烷脱氢（PDH）。结果表明，设计了T-钴(II)和金属钴的双功能位点，并且通过CO在金属钴上的歧化原位生成的碳可以覆盖无活性的金属钴并同时调整活性T-钴(II)的d带。更重要的是，提出预先沉积的碳层会降低T-钴(II)的电子密度并使d带中心更接近费米能级，从而促进PDH反应中的C-H活化。这项研究为利用无活性碳作为电子促进剂提供了新视角，并为制备高效的PDH及其他多相催化剂开辟了新机遇。
