Sulfur stabilizing metal nanoclusters on carbon at high temperatures

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.

Engineering the Electronic Interaction between Metals and Carbon Supports for Oxygen/Hydrogen Electrocatalysis

“…These results imply that the EMSI-dependent electronic structure changes of Pt single atom may play a determinant role in the catalysis. , DFT simulations uncovered that the electron enrichment on PtNC/S–C could optimize the H* binding energy on Pt and promote the decrease of Δ G H (Figure g). Besides, we also found that the enrichment of electrons over the Pt cluster can tune the selectivity of propane dehydrogenation and promote the catalytic selectivity to propene …”

“…Besides, we also found that the enrichment of electrons over the Pt cluster can tune the selectivity of propane dehydrogenation and promote the catalytic selectivity to propene. 43 Chen et.al reported a nitrogen-doped graphene-supported Ir single atom catalyst for ORR, in which the particle size effect induced change of EMSI was also involved. 38 They found that electrons transferred from a single Ir atom to the nearby N atoms in Ir−N 4 structure, while the Ir 19 cluster preserved the metallic state (see Figures 5h and 5i).…”

Advanced Carbon‐Based Nanocatalysts and their Application in Catalytic Conversion of Renewable Platform Molecules

“…In addition to nitrogen, sulfur is also used to fix and modify metals [5,48,58,59] . As shown in Table 2, the most common functions of S are to form metal–S species, [5,48,58,59,108] regulate the electronic state of metals, [5,58,74,108,109] and enhance their dispersion and stability [5,58,59,74,108,109] .…”

“…[5,48,58,59] As shown in Table 2, the most common functions of S are to form metal-S species, [5,48,58,59,108] regulate the electronic state of metals, [5,58,74,108,109] and enhance their dispersion and stability. [5,58,59,74,108,109] In addition, the interaction between metal and S can also change the reduction state of metal [108] and adjust the ability of metal to adsorb and desorb substrate/intermediate, [58,74] so as to optimize the efficiency of catalytic reaction. Liang and co-workers successfully prepared Sdoped carbon stabilized Pt nanoclusters (Pt/SÀ C).…”

“…Metal-S species [5,48,58,59,108] Regulate electronic structure of metal [5,58,74,108,109] Improve metal dispersion and stability [5,58,59,74,108,109] Change reduction state [108] Regulate the adsorption/desorption strength of substrate/ intermediate [58,74] Pyrolysis of S-containing precursor Solvent impregnation and meltcoating…”