Effect of cobalt speciation and the graphitization of the carbon matrix on the CO2 electroreduction activity of Co/N-doped carbon materials
Effect of cobalt speciation and the graphitization of the carbon matrix on the CO2 electroreduction activity of Co/N-doped carbon materials
复制标题
钴形态和碳基体石墨化对Co/N掺杂碳材料CO2电还原活性的影响
DOI：
10.1021/acsami.0c21920
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发表时间：
2021
影响因子：
9.5
通讯作者：
Juan Herranz*
中科院分区：
文献类型：
--
作者：
Kazuyuki Iwase,* Kathrin Ebner; Justus Diercks;Viktoriia Saveleva;Secil Unsal;Frank Krumeich;Takashi Harada;Itaru Honma;Shuji Nakanishi;Kazuhide Kamiya,* Thomas Schmidt;Juan Herranz*
二氧化碳的电还原被认为是工业过程中排放的二氧化碳甚至存在于环境中的二氧化碳增值的关键反应。具有原子分散CO - n位的钴氮共掺杂碳材料已被证明具有将二氧化碳还原为CO的优越活性和选择性。（如合成气），被视为一种附加价值的二氧化碳减排产品。这种催化剂可以通过热处理步骤合成，这意味着含co - n前驱体的碳化，但合成条件和相应材料的组成对其催化活性的详细影响尚未得到严格的研究。为此，在本工作中，我们合成了不同热处理温度的钴氮共掺杂碳材料，并研究了其表面形态和共形态与CO2-to-CO电还原活性之间的关系。我们的研究结果表明，原子分散的钴氮位点是CO生成的原因，同时表明当这些原子CO- n中心位于覆盖CO纳米颗粒的碳层中时，CO的选择性会提高，这些碳层覆盖了在较高热处理温度下合成的催化剂的特征。
The electroreduction of carbon dioxide is considered a key reaction for the valorization of CO2emitted in industrial processes or even present in the environment. Cobalt–nitrogen co-doped carbon materials featuring atomically dispersed Co–N sites have been shown to display superior activities and selectivities for the reduction of carbon dioxide to CO, which, in combination with H2(i.e., as syngas), is regarded as an added-value CO2-reduction product. Such catalysts can be synthesized using heat treatment steps that imply the carbonization of Co–N-containing precursors, but the detailed effects of the synthesis conditions and corresponding materials’ composition on their catalytic activities have not been rigorously studied. To this end, in the present work, we synthesized cobalt–nitrogen co-doped carbon materials with different heat treatment temperatures and studied the relation among their surface- and Co-speciation and their CO2-to-CO electroreduction activity. Our results reveal that atomically dispersed cobalt–nitrogen sites are responsible for CO generation while suggesting that this CO-selectivity improves when these atomic Co–N centers are hosted in the carbon layers that cover the Co nanoparticles featured in the catalysts synthesized at higher heat treatment temperatures.