School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University , Shanghai 200240, P. R. China.
Department of Colloid Chemistry, Max-Planck Institute of Colloids and Interfaces , Wissenschaftspark Golm, 14424 Potsdam, Germany.
J Am Chem Soc. 2017 Jan 18;139(2):811-818. doi: 10.1021/jacs.6b10710. Epub 2017 Jan 6.
Heterogeneous catalysts of inexpensive and reusable transition-metal are attractive alternatives to homogeneous catalysts; the relatively low activity of transition-metal nanoparticles has become the main hurdle for their practical applications. Here, the de novo design of a Mott-Schottky-type heterogeneous catalyst is reported to boost the activity of a transition-metal nanocatalyst through electron transfer at the metal/nitrogen-doped carbon interface. The Mott-Schottky catalyst of nitrogen-rich carbon-coated cobalt nanoparticles (Co@NC) was prepared through direct polycondensation of simple organic molecules and inorganic metal salts in the presence of g-CN powder. The Co@NC with controllable nitrogen content and thus tunable Fermi energy and catalytic activity exhibited a high turnover frequency (TOF) value (8.12 mol methyl benzoate mol Co h) for the direct, base-free, aerobic oxidation of benzyl alcohols to methyl benzoate; this TOF is 30-fold higher than those of the state-of-the-art transition-metal-based nanocatalysts reported in the literature. The presented efficient Mott-Schottky catalyst can trigger the synthesis of a series of alkyl esters and even diesters in high yields.
廉价且可重复使用的过渡金属的多相催化剂是均相催化剂的有吸引力的替代品；过渡金属纳米粒子的相对较低的活性已成为其实际应用的主要障碍。在此，报道了一种 Mott-Schottky 型多相催化剂的从头设计，通过在金属/氮掺杂碳界面处的电子转移来提高过渡金属纳米催化剂的活性。富氮碳涂层钴纳米粒子（Co@NC）的 Mott-Schottky 催化剂是通过简单的有机分子和无机金属盐在 g-CN 粉末存在下直接缩聚制备的。具有可控氮含量的 Co@NC 具有可调谐的费米能和催化活性，在直接、无碱、有氧条件下，对苄醇氧化为苯甲酸甲酯的反应表现出高的周转频率（TOF）值（8.12 mol 苯甲酸甲酯/mol Co h）；该 TOF 是文献中报道的最先进的基于过渡金属的纳米催化剂的 30 倍。所提出的高效 Mott-Schottky 催化剂可以引发一系列烷基酯甚至二酯的高产率合成。
