N‐doped carbon materials can be efficient and cost‐effective catalysts for the electrochemical CO2 reduction reaction (CO2RR). Activators are often used in the synthesis process to increase the specific surface area and porosity of these carbon materials. However, owing to the diversity of activators and the differences in physicochemical properties that these activators induce, the influence of activators used for the synthesis of N‐doped carbon catalysts on their electrochemical performance is unclear. In this study, a series of bagasse‐derived N‐doped carbon catalysts is prepared with the assistance of different activators to understand the correlation between activators, physicochemical properties, and electrocatalytic performance for the CO2RR. The properties of N‐doped carbon catalysts, such as N‐doping content, microstructure, and degree of graphitization, are found to be highly dependent on the type of activator applied in the synthesis procedure. Moreover, the overall CO2RR performance of the synthesized electrocatalysts is not determined only by the N‐doping level and the configuration of the N‐dopant, but rather by the overall surface chemistry, where the porosity and the degree of graphitization are jointly responsible for significant differences in CO2RR performance.

Nitrogen-doped (N-doped) carbon catalysts have been widely studied for electrochemical CO 2 reduction to CO. However, the correlation between the physicochemical properties of N-doped carbon catalysts and their electrocatalytic performance for the CO 2 RR is still unclear. Herein, a series of Ndoped biochar catalysts with different physicochemical properties were synthesized by tuning the carbonization temperature and N-doping level and used for the CO 2 RR to analyze the structure−performance relationship. The prepared catalysts exhibited massive differences in maximum faradaic efficiency to CO from 26.8 to 94.9% at around −0.8 to −0.9 V vs RHE. In addition, we find that simply increasing the specific surface area and N-doping level of the catalysts does not effectively improve the catalytic performance for the CO 2 RR. A multivariate correlation analysis reveals a negative correlation between the Ndoping content and the electrochemical performance. The porous structural properties exhibit a positive correlation to the FE CO but almost no correlation to j CO . Interestingly, improving the degree of graphitization, surface hydrophobicity, the abundance of defects, and optimizing the porosity of the N-doped biochar catalyst can efficiently enhance the catalytic performance for the CO 2 RR. We conclude that comprehensively analyzing the synergistic effect of various properties of N-doped biochar is critical to reveal structure−activity relationships.

Preparing supported nanoparticles with a well‐defined structure, uniform particle size, and composition using conventional catalyst synthesis methods, such as impregnation, precipitation, and deposition‐precipitation is challenging. Furthermore, these liquid phase methods require significant solvent consumption, which has sustainable issues and requires complex purification processes, usually leaving impurities on the catalyst, affecting its selectivity and activity. In this work, we employed atomic layer deposition (ALD, a vapor phase synthesis method) to synthesize electrocatalysts with well‐controlled core‐shell and alloy structures for CO2 reduction to formic acid. With this approach, the structural control of the catalysts is down to the atomic scale, and the effect of core‐shell and alloy structure on Pt−Pd bimetallic catalysts has been investigated. It is shown that the Pt−Pd alloy catalyst displays a 46 % faradaic efficiency toward formic acid, outperforming Pt@Pd and Pd@Pt core‐shell structures that show faradaic efficiencies of 22 % and 11 %, respectively. Moreover, both core‐shell bimetallic catalysts (Pd@Pt and Pt@Pd) are not stable under electroreduction conditions. These catalysts restructure to more thermodynamically stable structures, such as segregated clusters or alloy particles, during the electrochemical reduction reaction, altering the catalytic selectivity.