Sulfur stabilizing metal nanoclusters on carbon at high temperatures

Peng Yin,Xiao Luo,Xiao-Jun Wu,Junling Lu,Xusheng Zheng,Yanfu Ma,Sheng-Qi Chu,Si Chen,Hai-Wei Liang

doi:10.1038/s41467-021-23426-z

Abstract

Supported metal nanoclusters consisting of several dozen atoms are highly attractive for heterogeneous catalysis with unique catalytic properties. However, the metal nanocluster catalysts face the challenges of thermal sintering and consequent deactivation owing to the loss of metal surface areas particularly in the applications of high-temperature reactions. Here, we report that sulfur—a documented poison reagent for metal catalysts—when doped in a carbon matrix can stabilize ~1 nanometer metal nanoclusters (Pt, Ru, Rh, Os, and Ir) at high temperatures up to 700 °C. We find that the enhanced adhesion strength between metal nanoclusters and the sulfur-doped carbon support, which arises from the interfacial metal-sulfur bonding, greatly retards both metal atom diffusion and nanocluster migration. In catalyzing propane dehydrogenation at 550 °C, the sulfur-doped carbon supported Pt nanocluster catalyst with interfacial electronic effects exhibits higher selectivity to propene as well as more stable durability than sulfur-free carbon supported catalysts.

Highlights

Supported metal nanoclusters consisting of several dozen atoms are highly attractive for heterogeneous catalysis with unique catalytic properties
High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) measurements of the sulfur-doped carbon (S–C) supported Pt nanocluster (Pt/S–C) catalyst showed that numerous Pt nanoclusters with size in the range of 0.8–1.3 nm homogeneously distributed over the whole carbon matrix, without any large particles or nanocluster aggregates (Fig. 2a and Supplementary Fig. 1)
We further performed the density functional theory (DFT) calculations of the propane dehydrogenation (PDH) reaction paths on Pt38/S–Graphene, Pt38/Graphene, and Pt (111) surface to understand the attribution of the strong Pt–S interaction to the enhanced catalytic performance of Pt/S–C (Fig. 6c and Supplementary Figs. 32–34)

Summary

Introduction

Supported metal nanoclusters consisting of several dozen atoms are highly attractive for heterogeneous catalysis with unique catalytic properties. An inherent problem of metal nanoclusters for catalysis applications is their well-documented thermodynamic instability[13,14,15], as metal species tend strongly to grow into larger crystallites due to the sharply increased surface energy with the decrease of particle size, through the particle migration and coalescence (PMC) and/or Ostwald ripening (OR) processes[16,17] Such metal sintering inevitably leads to the loss of active surface area and the catalyst deactivation, especially for hightemperature catalytic reactions. The prepared Pt nanocluster catalysts exhibit high activity, selectivity, and long reaction lifetimes in the high-temperature reaction of propane dehydrogenation (PDH) to propylene at 550 °C, demonstrating the application potentials of the metal nanocluster catalysts for industrially relevant catalysis under realistic technical conditions

Methods

Results

Conclusion