Defect anchoring of atomically dispersed Pd on nitrogen-doped holey carbon nanotube for catalytic hydrogenation of nitroarenes

Abstract

High-density dispersion and efficient exposure of active metal sites are crucial for enhancing the catalytic activity of metal-based heterogeneous catalysts and improving the utilization of precious metal atoms. Increasing the surface to volume ratio by decreasing the size of metal nanoparticles is considered an ideal and straightforward strategy to increase catalytic activity. However, the generation of stable metal clusters or even single-atom metal species on supports is challenging since metal atoms are prone to agglomerate. In this work, we report a facile and practical method to anchor atomically dispersed Pd on an N-doped holey carbon nanotube (Pd/NHCNT) by efficiently strengthening metal-support interaction. Due to the unique characteristics of defected NHCNT support, highly dispersed Pd clusters and single atoms can be facilely introduced and anchored onto NHCNT. The resultant Pd/NHCNT catalyst exhibits a remarkable activity for nitroarenes hydrogenation with a turnover frequency as high as 1091.49 min−1, which surpasses the reported noble metal-based catalysts. Furthermore, theoretical simulations are applied for the understanding of the defect anchoring of atomically Pd and the interaction between active sites and substrate. The defect-induced anchoring approach provides a new avenue for designing and preparing other highly active atomic metal catalysts with high metal dispersion and can be applied to diverse organic reactions.