The ensemble effect of nitrogen doping and ultrasmall SnO2 nanocrystals on graphene sheets for efficient electroreduction of carbon dioxide
The ensemble effect of nitrogen doping and ultrasmall SnO2 nanocrystals on graphene sheets for efficient electroreduction of carbon dioxide
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DOI：
10.1016/j.apcatb.2018.08.044
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发表时间：
2018-12
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影响因子：
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通讯作者：
Baohua Zhang;Zhihao Guo;Z. Zuo;Wei-Chih Pan;Jintao Zhang
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文献类型：
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作者：
Baohua Zhang;Zhihao Guo;Z. Zuo;Wei-Chih Pan;Jintao Zhang
将二氧化碳(CO2)电还原为燃料和其他化学品是应对紧迫的气候和能源挑战的一种令人兴奋的方法。然而，传统电催化剂在二氧化碳还原反应(CO2RR)中的效率和选择性不理想是其主要障碍。为此，我们开发了一种简便有效的方法，通过原位转化策略在掺氮石墨烯上沉积超细SnO2纳米晶，从而获得高效的CO2RR。对比研究表明，这些电催化剂的电催化活性依赖于SnO2在石墨烯上的负载量和氮的掺杂。优化后的电催化剂在低过电位(∼0.6 V)下对CO2电还原生成甲酸盐和一氧化碳具有较高的选择性，法拉第效率为∼89%，电流密度为∼2 1.3 mA/cm 2。此外，优化的电催化剂在20 h内表现出良好的稳定性，这可能是由于高度分散的超细SnO2纳米晶与石墨烯表面的氮掺杂之间的系综效应所致。为开发高效的CO2还原催化剂提供了一种合理的设计策略。
The electroreduction of carbon dioxide (CO2) into fuels and other chemicals is an exciting approach to address the urgent climate and energy challenges. However, the unsatisfied efficiency and selectivity for CO2reduction reaction (CO2RR) with conventional electrocatalysts are the major obstacles. Herein, a facile and effective method is developed to deposit ultrasmall SnO2nanocrystals on nitrogen-doped graphene via in-situ conversion strategies for highly efficient CO2RR. The comparison studies reveal that the electrocatalytic activity of such electrocatalysts relies on the loading of SnO2on graphene and the nitrogen doping. The optimal electrocatalyst exhibits a high selectivity for CO2electroreduction to formate and carbon monoxide at low overpotential (∼ 0.6 V) with a faradaic efficiency of ∼ 89% and a current density of ∼21.3 mA/cm2. Additionally, the optimal electrocatalyst shows an excellent stability for 20 h. The good performance would be contributed to the ensemble effect between the highly dispersed ultrasmall SnO2nanocrystals and the nitrogen doping on graphene sheets. This work thus provides a rational design strategy for developing efficient CO2reduction catalysts.