Optimizing FeNC Materials as Electrocatalysts for the CO 2 Reduction Reaction: Heat‐Treatment Temperature, Structure and Performance Correlations

• Published in: ChemCatChem 2019-10, Vol.11 (19), p.4854-4861
• Main Authors: González‐Cervantes, Eduardo, Crisóstomo, Anaí Arellano, Gutiérrez‐Alejandre, Aída, Varela, Ana Sofía
• Format: Article
• Language: English
• ISSN: 1867-3880; 1867-3899
• DOI: 10.1002/cctc.201901196

The direct CO 2 electrochemical reduction reaction (CO2RR) into carbon‐based chemicals has attracted tremendous attention as a sustainable process for CO 2 utilization. The viability of the process, however, is contingent on finding efficient catalysts based on earth abundant elements. Carbon‐based solid catalyst materials doped with nitrogen and transition metals (M−N−C) have emerged as a cost‐efficient alternative for the direct electrochemical reduction of CO 2 into CO. These materials contain different N functionalities and MN x moieties which could be involved in the catalytic process. With the aim of gaining insight into the role of these different active sites and how to control their concentration we have prepared 5 polyaniline derived FeNC catalysts by changing the temperature of the heat treatment (750–1050 °C). We observed that it is possible to tune the ratio of the different N functionalities by changing the pyrolysis temperature. Furthermore, this had a clear impact on the catalytic performance of this family of FeNC materials. In particular, a higher temperature correlated with a larger FeN x concentration resulting in a high selectivity toward the CO2RR. These results indicate that FeN x moieties play a predominant role in the catalytic process and that the incorporation of such sites to the carbon structure is enhanced by the heat‐treatment temperature.