Construction of High-Density Fe Clusters Embedded in a Porous Carbon Nitride Catalyst with Effectively Selective Transformation of Benzene
Xiao Dong Chen, Xiao Dong Chen, Lanlan Cheng, Yiguo Yang, Xiufang Chen, Xiufang Chen, Fengtao Chen, Wangyang Lü
Abstract
An Fe-based heterogeneous catalyst is an attractive Fenton-like catalyst for phenol synthesis due to many advantages. Nevertheless, it is challenging to control the particle size in various high-loading Fe-based materials, which limits its activity and selectivity. In this work, ultra-small Fe clusters embedded in a 3D porous interconnected open-framework g-C 3 N 4 (denoted FeN x /CCN) were successfully fabricated by the combination of a mechanochemical reaction with one-step pyrolysis. Various characterization results showed that ultra-small Fe clusters with a high loading of 32% were uniformly distributed in the hierarchical porous carbon nitride, which offered an access for faster transportation of charge carriers. Fe sites were probably coordinated with carbon nitride by Fe 2+ –C≡ N–Fe 3+ and Fe–N x bonding. High-density Fe clusters could provide abundant active sites and improve the light absorption and the activating ability of H 2 O 2 . By taking advantage of semiconductor functions in combination with a rich porous structure and high-density active sites, the novel Fe cluster catalyst exhibited high activity and stability in phenol synthesis, with a maximum phenol yield of 28.1% in visible light. Combining the experimental results with Fenton chemistry, we proposed a possible photocatalytic reaction mechanism. Our work will give valuable information on the development of active metal cluster nanocatalysts for organic synthesis.