Article

Asymmetric Triple-Atom Sites Confined in Ternary Oxide Enabling Selective CO<sub>2</sub> Photothermal Reduction to Acetate

Juncheng ZhuHefei National Laboratory for Physical Sciences at the Microscale, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, ChinaWeiwei ShaoHefei National Laboratory for Physical Sciences at the Microscale, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, ChinaXiaodong LiHefei National Laboratory for Physical Sciences at the Microscale, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, ChinaXingchen JiaoHefei National Laboratory for Physical Sciences at the Microscale, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, ChinaJunfa ZhuHefei National Laboratory for Physical Sciences at the Microscale, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, ChinaYongfu SunHefei National Laboratory for Physical Sciences at the Microscale, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, ChinaYi XieHefei National Laboratory for Physical Sciences at the Microscale, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, China

2021en

ABI

Abstract

Light-induced heat is largely neglected in traditional photocatalytic systems, especially for the thermodynamically and kinetically challenging CO2 reduction to C2 fuels. Herein, we first design asymmetric Metal1–O–Metal2 triple-atom sites confined in phenakite to facilitate C–C coupling and employ photoinduced heat to increase molecular thermal vibration and accelerate CO2 reduction to C2 fuels. Using O-vacancy-rich Zn2GeO4 nanobelts as prototypes, quasi in situ Raman spectra disclose the Zn–O–Ge triatomic sites are likely the reactive sites. Density functional theory calculations reveal that the asymmetric Zn–O–Ge sites could promote C–C coupling through inducing distinct charge distributions of neighboring C1 intermediates, whereas the created O vacancies could lower the energy barrier of the rate-determining hydrogenation step from 1.46 to 0.67 eV. Catalytic performances under different testing conditions demonstrate that light initiates the CO2 reduction reaction. In situ Fourier-transform infrared spectra and D2O kinetic isotopic effect experiments disclose that light-induced heat kinetically triggers C–C coupling and accelerates OCCO* hydrogenation via providing abundant hydrogen species. Consequently, in a simulated air atmosphere under 0.1 W/cm2 illumination at 348 K, the O-vacancy-rich Zn2GeO4 nanobelts demonstrate an acetate output of 12.7 μmol g–1 h–1, a high acetate selectivity of 66.9%, a considerable CO2-to-CH3COOH conversion ratio of 29.95%, and a stability of up to 220 h.

Identifiers

DOI: 10.1021/jacs.1c08033

Citations and references

Cited by 30 references

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