Recover the activity of sintered supported catalysts by nitrogen-doped carbon atomization

Huang Zhou ,Wei Liu ,Zhiyuan Wang ,Weng‐Chon Cheong ,Wenyu Wang ,Xiaoqian Wang ,Xun Hong ,Jing Liu ,Benjin Jin ,Jun Luo ,Shiqiang Wei ,Takeshi Yao ,Tongwei Yuan ,Min Chen ,Yafei Zhao ,Zhijun Li ,Fangyao Zhou ,Jie Xu ,Yancai Yao ,Chao Zhao ,Rongbo Sun ,Haoran Sun ,Yuen Wu

doi:10.1038/s41467-019-14223-w

Abstract

The sintering of supported metal nanoparticles is a major route to the deactivation of industrial heterogeneous catalysts, which largely increase the cost and decrease the productivity. Here, we discover that supported palladium/gold/platinum nanoparticles distributed at the interface of oxide supports and nitrogen-doped carbon shells would undergo an unexpected nitrogen-doped carbon atomization process against the sintering at high temperatures, during which the nanoparticles can be transformed into more active atomic species. The in situ transmission electron microscopy images reveal the abundant nitrogen defects in carbon shells provide atomic diffusion sites for the mobile atomistic palladium species detached from the palladium nanoparticles. More important, the catalytic activity of sintered and deactivated palladium catalyst can be recovered by this unique N-doped carbon atomization process. Our findings open up a window to preparation of sintering-resistant single atoms catalysts and regeneration of deactivated industrial catalysts.

Highlights

The sintering of supported metal nanoparticles is a major route to the deactivation of industrial heterogeneous catalysts, which largely increase the cost and decrease the productivity
The N-doped carbon atomization process is opposite to the conventional sintering, during which the sintering of supported Pd/Au/Pt NPs on oxide supports is largely prohibited by covering the NPs with a N-doped carbon shell
A polydopamine (PDA) layer was deposited on the surface to form a core–shell structure, as evidenced by a typical stretching vibration for N/O–H at 3450 cm−1 and a bending vibration of N–H at 1615 cm−1 in Fourier-transformed infrared (FT-IR) spectroscopy[5] (Supplementary Fig. 4)

Summary

Introduction

The sintering of supported metal nanoparticles is a major route to the deactivation of industrial heterogeneous catalysts, which largely increase the cost and decrease the productivity. To investigate the intrinsic mechanism of high temperature and N-doped carbon atomization, the evolution process from Pd NPs/TiO2@PDA to Pd SAs/TiO2@C was further traced by in situ TEM.

Results

Conclusion