Quantum-Dot-Derived Catalysts for CO2 Reduction Reaction
Quantum-Dot-Derived Catalysts for CO2 Reduction Reaction
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用于二氧化碳还原反应的量子点衍生催化剂
DOI：
10.1016/j.joule.2019.05.010
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发表时间：
2019-07-17
期刊：
影响因子：
39.8
通讯作者：
Sargent, Edward H.
中科院分区：
文献类型：
--
作者：
Liu, Min;Liu, Mengxia;Sargent, Edward H.
缺陷位点通常被认为是催化剂设计中的关键活性位点。提高活性的一个有希望的策略是实现高密度均匀分散的原子缺陷；然而，这在金属中很少实现。我们假设可以通过在CO2还原反应（CO2RR）中合成量子点（QDs）及其电化学还原得到富空位催化剂。在这里，我们报道了具有高达20 vol %空位的qd衍生催化剂（qddc）在与可逆氢电极（RHE）相比，分别在-0.2、-0.3和-0.9 V的低电位下电合成甲酸盐、一氧化碳和乙烯时，具有创纪录的16、19和25 mAcm（-2）的电流密度。经过80小时的CO2RR后，材料是稳定的。这些CO2RR在水溶液中的性能比先前报道的催化剂高出2倍。x射线吸收光谱和计算研究表明，空位产生了增强CO2RR的局部原子和电子结构。
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 2X. Together, X-ray absorption spectroscopy and computational studies reveal that the vacancies produce a local atomic and electronic structure that enhances CO2RR.