@article{Li2021, 
author = {Mufan Li and Bei Zhang and Tao Cheng and Sunmoon Yu and Sheena Louisia and Chubai Chen and Shouping Chen and Stefano Cestellos-Blanco and William A. Goddard III and Peidong Yang},
title = {Sulfur-doped graphene anchoring of ultrafine Au25 nanoclusters for electrocatalysis},
year = {2021},
journal = {Nano Research},
volume = {14},
number = {10},
pages = {3509-3513},
keywords = {electrocatalysis, gold nanoclusters, nitrogen reduction reaction, sulfur-doped graphene, anchoring effect},
url = {https://www.sciopen.com/article/10.1007/s12274-021-3561-2},
doi = {10.1007/s12274-021-3561-2},
abstract = {The biggest challenge of exploring the catalytic properties of under-coordinated nanoclusters is the issue of stability. We demonstrate herein that chemical dopants on sulfur-doped graphene (S-G) can be utilized to stabilize ultrafine (sub-2 nm) Au25(PET)18 clusters to enable stable nitrogen reduction reaction (NRR) without significant structural degradation. The Au25@S-G exhibits an ammonia yield rate of 27.5 μgNH3·mgAu-1·h-1 at -0.5 V with faradic efficiency of 2.3%. More importantly, the anchored clusters preserve ~ 80% NRR activity after four days of continuous operation, a significant improvement over the 15% remaining ammonia production rate for clusters loaded on undoped graphene tested under the same conditions. Isotope labeling experiments confirmed the ammonia was a direct reaction product of N2 feeding gas instead of other chemical contaminations. Ex-situ X-ray photoelectron spectroscopy and X-ray absorption near-edge spectroscopy of post-reaction catalysts reveal that the sulfur dopant plays a critical role in stabilizing the chemical state and coordination environment of Au atoms in clusters. Further ReaxFF molecular dynamics (RMD) simulation confirmed the strong interaction between Au nanoclusters (NCs) and S-G. This substrate-anchoring process could serve as an effective strategy to study ultrafine nanoclusters' electrocatalytic behavior while minimizing the destruction of the under-coordinated surface motif under harsh electrochemical reaction conditions.}
}