DFT Study on the CO2 Reduction to C2 Chemicals Catalyzed by Fe and Co Clusters Supported on N-Doped Carbon

Abstract

The catalytic conversion of CO2 to C2 products through the CO2 reduction reaction (CO2RR) offers the possibility of preparing carbon-based fuels and valuable chemicals in a sustainable way. Herein, various Fen and Co5 clusters are designed to screen out the good catalysts with reasonable stability, as well as high activity and selectivity for either C2H4 or CH3CH2OH generation through density functional theory (DFT) calculations. The binding energy and cohesive energy calculations show that both Fe5 and Co5 clusters can adsorb stably on the N-doped carbon (NC) with one metal atom anchored at the center of the defected hole via a classical MN4 structure. The proposed reaction pathway demonstrates that the Fe5-NC cluster has better activity than Co5-NC, since the carbon–carbon coupling reaction is the potential determining step (PDS), and the free energy change is 0.22 eV lower in the Fe5-NC cluster than that in Co5-NC. However, Co5-NC shows a better selectivity towards C2H4 since the hydrogenation of CH2CHO to CH3CHO becomes the PDS, and the free energy change is 1.08 eV, which is 0.07 eV higher than that in the C-C coupling step. The larger discrepancy of d band center and density of states (DOS) between the topmost Fe and sub-layer Fe may account for the lower free energy change in the C-C coupling reaction. Our theoretical insights propose an explicit indication for designing new catalysts based on the transition metal (TM) clusters supported on N-doped carbon for multi-hydrocarbon synthesis through systematically analyzing the stability of the metal clusters, the electronic structure of the critical intermediates and the energy profiles during the CO2RR.

M−N−C Materials for Electrochemical Reduction Reactions: Recent Strategies for Improving Electrocatalytic Activity and Stability

“…This, however, made Ni−N−C systems unfit for CO conversion to hydrocarbons. In agreement, the ability of the AC in M−N−C to strongly bind CO is a crucial factor for defining its activity towards CO 2 hydrogenation [114] …”

“…In agreement, the ability of the AC in MÀ NÀ C to strongly bind CO is a crucial factor for defining its activity towards CO 2 hydrogenation. [114] Concerning the nature of the metal in the active sites, the better activity of the CÀ C coupling reaction (i. e., for C 2 H 2 or CH 3 CH 2 OH generation) on Fe 5 NC compared to Co 5 NC has been attributed to the bigger discrepancy of the d electrons of the two CO-adsorbing Fe atoms. [114] A more general conclusion reported that MÀ NÀ C materials, with discrete and narrow metal d-states on their ACs, could be active CO 2 RR catalysts, under the condition that HER is not competitive.…”

“…[114] Concerning the nature of the metal in the active sites, the better activity of the CÀ C coupling reaction (i. e., for C 2 H 2 or CH 3 CH 2 OH generation) on Fe 5 NC compared to Co 5 NC has been attributed to the bigger discrepancy of the d electrons of the two CO-adsorbing Fe atoms. [114] A more general conclusion reported that MÀ NÀ C materials, with discrete and narrow metal d-states on their ACs, could be active CO 2 RR catalysts, under the condition that HER is not competitive. [90] In addition to the optimum BE of CO 2 RR intermediates, the electronic structure of the AC can also affect the selectivity of the MÀ NÀ C materials.…”

Recent Advancement in Piezopolarization Induced Photocatalytic H2O2 Production: Fundamentals, Theoretical Insights, and Future Endeavors

“…81,82 Computational/theoretical investigation is one of the most fundamental routes, explored by many scientists to help the research community achieve the goal of harvesting and storing solar energy in the most suitable energy mode like H 2 , O 2 , and hydrocarbon-based fuels. 83,84 In this section, we briefly disclose the best possible crystal structure analysis and various model energy calculations implemented in the solid state as well as catalytic research by the help of various software and the relationship in materials design, enriching stability and finding the mechanism of photocatalytic reactions.…”

“…This approach allows for a deeper understanding of fundamental processes that cannot be directly observed in experimental settings. Computational materials science can be used to envisage many usual properties of materials, such as predicting activation energies of reactions, finding minimum energy pathways, and seeing electronic properties of materials not found in physical experimentation, thus influencing the discovery of new materials. , Computational/theoretical investigation is one of the most fundamental routes, explored by many scientists to help the research community achieve the goal of harvesting and storing solar energy in the most suitable energy mode like H 2 , O 2 , and hydrocarbon-based fuels. , In this section, we briefly disclose the best possible crystal structure analysis and various model energy calculations implemented in the solid state as well as catalytic research by the help of various software and the relationship in materials design, enriching stability and finding the mechanism of photocatalytic reactions. We also assemble the DFT computed sets to explore the mechanism of the photogenerated exciton separation/transfer and the mechanism of the catalytic reaction by illustrating a few representative examples.…”