Open AccessAtomically Dispersed Copper Sites in a Metal–Organic Framework for Reduction of Nitrogen Dioxide
Author(s) -
Yujie Ma,
Xue Han,
Shaojun Xu,
Zi Wang,
Weiyao Li,
Iván da Silva,
Sarayute Chansai,
Daniel Lee,
Yichao Zou,
Marek Nikiel,
Pascal Manuel,
Alena M. Sheveleva,
Floriana Tuna,
Eric J. L. McInnes,
Yongqiang Cheng,
Svemir Rudić,
Anibal J. RamirezCuesta,
Sarah J. Haigh,
Christopher Hardacre,
Martin Schröder,
Sihai Yang
Publication year - 2021
Publication title -
journal of the american chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.115
H-Index - 612
eISSN - 1520-5126
pISSN - 0002-7863
DOI - 10.1021/jacs.1c03036
Subject(s) - catalysis , copper , electron paramagnetic resonance , selective catalytic reduction , spectroscopy , materials science , scanning transmission electron microscopy , infrared spectroscopy , chemistry , inorganic chemistry , nanotechnology , transmission electron microscopy , nuclear magnetic resonance , organic chemistry , physics , quantum mechanics
Metal-organic framework (MOF) materials provide an excellent platform to fabricate single-atom catalysts due to their structural diversity, intrinsic porosity, and designable functionality. However, the unambiguous identification of atomically dispersed metal sites and the elucidation of their role in catalysis are challenging due to limited methods of characterization and lack of direct structural information. Here, we report a comprehensive investigation of the structure and the role of atomically dispersed copper sites in UiO-66 for the catalytic reduction of NO 2 at ambient temperature. The atomic dispersion of copper sites on UiO-66 is confirmed by high-angle annular dark-field scanning transmission electron microscopy, electron paramagnetic resonance spectroscopy, and inelastic neutron scattering, and their location is identified by neutron powder diffraction and solid-state nuclear magnetic resonance spectroscopy. The Cu/UiO-66 catalyst exhibits superior catalytic performance for the reduction of NO 2 at 25 °C without the use of reductants. A selectivity of 88% for the formation of N 2 at a 97% conversion of NO 2 with a lifetime of >50 h and an unprecedented turnover frequency of 6.1 h -1 is achieved under nonthermal plasma activation. In situ and operando infrared, solid-state NMR, and EPR spectroscopy reveal the critical role of copper sites in the adsorption and activation of NO 2 molecules, with the formation of {Cu(I)···NO} and {Cu···NO 2 } adducts promoting the conversion of NO 2 to N 2 . This study will inspire the further design and study of new efficient single-atom catalysts for NO 2 abatement via detailed unravelling of their role in catalysis.