Efficient electrochemical reduction of CO2 into CO promoted by sulfur vacancies
Efficient electrochemical reduction of CO2 into CO promoted by sulfur vacancies
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DOI：
10.1016/j.nanoen.2019.03.024
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发表时间：
2019-06
期刊：
影响因子：
17.6
通讯作者：
Binhao Qin;Yuhang Li;Hongjuan Wang;Guangxing Yang;Yong Cao;Hao Yu;Qiao Zhang;Hong Liang;F. Peng
中科院分区：
文献类型：
--
作者：
Binhao Qin;Yuhang Li;Hongjuan Wang;Guangxing Yang;Yong Cao;Hao Yu;Qiao Zhang;Hong Liang;F. Peng
电化学转化二氧化碳（CO2）为有用的化学品已经吸引了大量的关注，以储存能量和减少温室效应。本文报道了一种新型硫化镉包覆碳纳米管电催化剂，其CO2还原反应（CO2 RR）的法拉第效率（FE）高达95%。通过电子顺磁共振谱（EPR）、原位微分电化学质谱（DEMS）和电感耦合等离子体光谱（ICP）的研究，我们清楚地证明了在CO_2RR中硫空位（S-空位）在催化剂表面原位生成。随着S-空位的增加，CO2 RR催化剂对CO的催化活性显著提高，电荷转移电阻降低。结合原位红外吸收光谱和密度泛函理论计算，可以得出结论：S空位的形成改变了催化剂表面的电子密度，降低了COOH → CO → CO转化的能垒。最后，我们尝试了在自然光条件下利用太阳能电池板进行CO2的电化学还原，计算了CdS-CNT催化剂上太阳能到CO的能量转换效率，展望了其应用前景。
Electrochemical conversion of carbon dioxide (CO2) into useful chemicals has attracted a lot of attention to store energy and reduce the greenhouse effect. Herein, a new electrocatalyst of carbon nanotubes coated with cadmium sulfide is reported, the faradaic efficiency (FE) of CO2reduction reaction (CO2RR) to carbon monoxide (CO) is as high as 95%. We clearly demonstrate that sulfur vacancies (S-vacancies) arein-situgenerated on the catalyst surface in CO2RR, which is evidenced by electron paramagnetic resonance spectra (EPR),in-situdifferential electrochemical mass spectrometry (DEMS) and inductively-coupled plasma spectrometer (ICP). With the increase of S-vacancies, the catalytic activity of CO2RR to CO improve significantly and the charge-transfer resistance decrease. Combined within-situinfrared absorption spectroscopy and density functional theory calculations, it can be concluded that the formation of S-vacancies changes the electron density of the catalyst surface and decreases the energy barrier for the conversion of COOH∗to CO∗. Finally, we tried to power electrochemical reduction of CO2with solar panel under natural light conditions, the energy conversion efficiency on CdS-CNT catalyst from solar energy to CO has been calculated, predicting a hopeful application prospect in the future.