Fe and N Co-Doped Porous Carbon Nanospheres with High Density of Active Sites for Efficient CO2 Electroreduction
Fe and N Co-Doped Porous Carbon Nanospheres with High Density of Active Sites for Efficient CO2 Electroreduction
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DOI：
10.1021/acs.jpcc.9b02195
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发表时间：
2019-07-11
影响因子：
3.7
通讯作者：
Yang, Hui
中科院分区：
文献类型：
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作者：
Chen, Yubin;Zou, Liangliang;Yang, Hui
为了提高过渡金属与氮共掺杂碳（M-N-C）在CO2电还原反应中的电催化性能，通过高分辨率TEM和EXAFS分析，我们制备了一种铁与氮共掺杂的多孔碳纳米球（Fe-N- pc），该纳米球具有高密度的单原子铁活性位点和少量的铁簇，并利用SiO2作为保护壳来限制孤立的铁原子，并捕获挥发性含N物质。Fe掺杂量最高可达3.9%。Fe-N-PC催化剂在-0.49 V下表现出优异的CO转化性能，具有较高的法拉第效率（接近90%）和显著的CO电流密度（11.44 mA cm(-2)）。探针分析和选择性化学修饰表明，Fe原子和N原子的正交c原子协同作用增强了CO2RR活性。DFT计算表明，无定形Fe团簇的存在有利于CO从催化剂表面的脱附，从而进一步提高了CO2RR活性。本工作提出了一种合成具有高密度单原子活性位的先进M-N-C材料的一般策略，该材料可作为CO2RR， ORR等的高效电催化剂。
To enhance the electrocatalytic performance of transition metal and nitrogen codoped carbon (M-N-C) for the CO2 electroreduction reaction, we present a Fe and N codoped porous carbon nanosphere (Fe-N-PC) with a high density of single-atom iron active sites and a few Fe clusters, as indicated by high-resolution TEM and EXAFS, using SiO2 as the protecting shell to restrict isolated Fe atoms and to trap the volatile N-containing species. The Fe doping content can reach as high as 3.9 wt %. The Fe-N-PC catalyst exhibits an excellent performance for converting CO2 to CO with high Faradaic efficiency (similar to 90%) and remarkable partial CO current density (11.44 mA cm(-2)) at -0.49 V. Probing analysis and selective chemical modification reveal that both Fe atom and ortho-C of N atoms play a synergetic role in enhancing CO2RR activity. DFT calculations reveal that the presence of amorphous Fe clusters can facilitate the desorption of CO from the surface of the catalyst, thus further improving the CO2RR activity. This work presents a general strategy to synthesize advanced M-N-C material with high density of single atom active sites, which could be used as an efficient electrocatalyst for CO2RR, ORR et al.