Theoretical insights into catalytic CO2 hydrogenation over single-atom (Fe or Ni) incorporated nitrogen-doped graphene

Single Metal Atom Catalyst Supported on g-C3N4 for Formic Acid Dehydrogenation: A Combining Density Functional Theory and Machine Learning Study

“…The formic acid cycle is an attractive carbon-neutral energy system with high economic viability. With the release of hydrogen, the accompanying CO 2 can promote its hydrogenation to formic acid by using similar or even the same catalytically active sites, thereby achieving sustainable conversion. , A large number of recent theoretical studies have also shown that a single metal atom embedded in the N-doped graphene or C 2 N sheet shows great activity and selectivity for the hydrogenation of CO 2 to HCOOH. − For M@g-C 3 N 4 , it can be seen from the energy barrier plot of formic acid dehydrogenation on the Rh-, Pd-, and Pt@g-C 3 N 4 systems that the relative energy of intermediates and transition states decreases slightly in the hydrogenation process of CO 2 to formic acid, and the energy barrier of each step is relatively low. Therefore, we propose that the Rh-, Pd-, and Pt@g-C 3 N 4 systems can be used as effective bifunctional catalysts for the dehydrogenation and synthesis of formic acid.…”

Rational Design of Main Group Metal-Embedded Nitrogen-Doped Carbon Materials as Frustrated Lewis Pair Catalysts for CO2 Hydrogenation to Formic Acid

“…6,16,18−20 Experimental and theoretical studies have shown that there is a high probability of pyridine N formation in N-atom-doped graphenes, 21−25 and the pyridine N structure can significantly improve the surface activity of the catalysts. 16,18,22,26,27 Studies have confirmed that single-metalembedded pyridine N materials have improved catalytic performance for CO 2 reduction. 6,16,18,26 For instance, Esrafili et al 16 investigated the single-Co-incorporated nitrogen-doped graphene for CO 2 hydrogenation and showed that CoN 3 -Gr can be used as a promising catalyst, and Hou et al 28 showed that the single-Ni-dispersed N-doped carbon (NC) nanotube with Ni− N active sites enhances the reduction of CO 2 to CO.…”

“…16,18,22,26,27 Studies have confirmed that single-metalembedded pyridine N materials have improved catalytic performance for CO 2 reduction. 6,16,18,26 For instance, Esrafili et al 16 investigated the single-Co-incorporated nitrogen-doped graphene for CO 2 hydrogenation and showed that CoN 3 -Gr can be used as a promising catalyst, and Hou et al 28 showed that the single-Ni-dispersed N-doped carbon (NC) nanotube with Ni− N active sites enhances the reduction of CO 2 to CO. In addition, the reported SACs for CO 2 hydrogenation to HCOOH include other combinations based on other N-doped carbon substrates and single transition metal atoms as active sites.…”

“…), and boron nitride (BN)-based materials are often used as substrates due to their large specific surface areas and unique physical and chemical properties. − For instance, Sredojević et al demonstrated that Ru-embedded graphene has better catalytic activity and stability than Cu-embedded graphene, and Ali et al explored the CO 2 conversion to HCOOH by single Cu, Pd, and Ru supported on monovacancy-defective graphene (m-VacG) and found that Pd supported on m-VacG shows the highest activity. While precious transition metals have good catalytic performance in general, the scarcity, high cost, toxicity, and environmental issues associated with them impose challenges for researchers to find alternative solutions using earth-abundant and non-noble metals and main group elements. ,− For SACs, it should be noted that the atoms or functional groups surrounding the metal active center can influence the electronic structure of the center and eventually modulate the catalytic properties. ,,− Experimental and theoretical studies have shown that there is a high probability of pyridine N formation in N-atom-doped graphenes, − and the pyridine N structure can significantly improve the surface activity of the catalysts. ,,,, Studies have confirmed that single-metal-embedded pyridine N materials have improved catalytic performance for CO 2 reduction. ,,, For instance, Esrafili et al investigated the single-Co-incorporated nitrogen-doped graphene for CO 2 hydrogenation and showed that CoN 3 -Gr can be used as a promising catalyst, and Hou et al showed that the single-Ni-dispersed N-doped carbon (NC) nanotube with Ni–N active sites enhances the reduction of CO 2 to CO. In addition, the reported SACs for CO 2 hydrogenation to HCOOH include other combinations based on other N-doped carbon substrates and single transition metal atoms as active sites. ,, Thus, it is of great interest and potential to optimize the substrates in SACs.…”

Unraveling the Catalytic Performance of the Nonprecious Metal Single-Atom-Embedded Graphitic s-Triazine-Based C3N4 for CO2 Hydrogenation

“…Huang et al found that the Faraday efficiency for the electrocatalytic reduction of CO 2 to HCOOH can be remarkably enhanced on the single Mo atom loaded N-doped graphene (Mo@NG) compared to N-doped graphene (NG) . In addition, some studies have reported that single-atom Fe-, Co-, or Al-incorporated 2D substrates can also promote CO 2 hydrogenation. − However, the main product of CO 2 hydrogenation catalyzed by such SACs is usually HCOOH, while the formation of other C1 products is rarely reported. Herein, a crucial issue then arises: Is there a metal-embedded SAC catalyst that can produce different C1 products of CO 2 hydrogenation such as CH 3 OH?…”