Atomically-precise dopant-controlled single cluster catalysis for electrochemical nitrogen reduction.

Yao, Chuanhao; Guo, Na; Xi, Shibo; Xu, Cong-Qiao; Liu, Wei; Zhao, Xiaoxu; Li, Jing; Fang, Hanyan et al. · Nat Commun · 2020

basic_science · Level V

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Abstract

The ability to precisely engineer the doping of sub-nanometer bimetallic clusters offers exciting opportunities for tailoring their catalytic performance with atomic accuracy. However, the fabrication of singly dispersed bimetallic cluster catalysts with atomic-level control of dopants has been a long-standing challenge. Herein, we report a strategy for the controllable synthesis of a precisely doped single cluster catalyst consisting of partially ligand-enveloped Au<sub>4</sub>Pt<sub>2</sub> clusters supported on defective graphene. This creates a bimetal single cluster catalyst (Au<sub>4</sub>Pt<sub>2</sub>/G) with exceptional activity for electrochemical nitrogen (N<sub>2</sub>) reduction. Our mechanistic study reveals that each N<sub>2</sub> molecule is activated in the confined region between cluster and graphene. The heteroatom dopant plays an indispensable role in the activation of N<sub>2</sub> via an enhanced back donation of electrons to the N<sub>2</sub> LUMO. Moreover, besides the heteroatom Pt, the catalytic performance of single cluster catalyst can be further tuned by using Pd in place of Pt as the dopant.