Quantum-Dot-Derived Catalysts for CO2 Reduction Reaction
Abstract
Defect sites are often proposed as key active sites in the design of catalysts. A promising strategy for improving activity is to achieve a high density of homogeneously dispersed atomic defects; however, this is seldom accomplished in metals. We hypothesize that vacancy-rich catalysts could be obtained through the synthesis of quantum dots (QDs) and their electrochemical reduction during the CO2 reduction reaction (CO2RR). Here, we report that QD-derived catalysts (QDDCs) with up to 20 vol % vacancies achieve record current densities of 16, 19, and 25 mAcm‑2 with high faradic efficiencies in the electrosynthesis of formate, carbon monoxide, and ethylene at low potentials of –0.2, –0.3, and –0.9 V versus reversible hydrogen electrode (RHE), respectively. The materials are stable after 80 hr of CO2RR. These CO2RR performances in aqueous solution surpass those of previously reported catalysts by 2×. Together, X-ray absorption spectroscopy and computational studies reveal that the vacancies produce a local atomic and electronic structure that enhances CO2RR.
- Publication:
-
Joule
- Pub Date:
- July 2019
- DOI:
- 10.1016/j.joule.2019.05.010
- Bibcode:
- 2019Joule...3.1703L
- Keywords:
-
- CO<SUB loc="post">2</SUB> reduction reaction;
- quantum dots;
- in situ electrochemical reduction;
- vacancy-rich;
- metallic nanocrystals;
- X-ray absorption spectroscopy;
- electronic structure