Screened Fe₃ and Ru₃ Single-Cluster Catalysts Anchored on MoS₂ Supports for Selective Hydrogenation of CO₂

Abstract

Efficient CO2 hydrogenation into valuable products is a promising strategy to address environmental issues and achieve green development goals, yet developing highly active and selective catalysts still remains a major challenge. The single-cluster catalysts frequently exhibit unexpected catalytic performance for complex reactions in heterogeneous catalysis due to the synergistic interaction between the active atoms. In this work, we have proposed candidate catalysts with Fe3 and Ru3 clusters anchored at the S vacancies on the MoS2 substrate for highly selective CO2 hydrogenation, which is screened from a series of transition-metal clusters including Fe3, Co3, Ni3, Ru3, Rh3, and Pd3 by employing density functional theory calculations. The electron structure analysis reveals that the orbital interactions between metal hydride and CO2 dominate the adsorption modes of CO2 molecules on M3 clusters, wherein CO2 forms a symmetrical η1–C adsorption mode on the Fe3 cluster and an asymmetric η2–C,O adsorption mode on the Ru3 cluster, thereby leading to different CO2 hydrogenation pathways. Furthermore, the underlying reaction mechanisms for CO2 hydrogenation on Fe3/MoS2–v and Ru3/MoS2–v have been explored, and the M3 clusters are suggested to act as electron reservoirs throughout the whole hydrogenation reaction. Combining with microkinetic simulations, we have showed the highly selective reactivity toward methanol formation on Fe3/MoS2–v and ethanol formation on Ru3/MoS2–v . Our work provides in-depth atomic-scale insights into the mechanism of CO2 transformation in transition-metal single-cluster catalysis, which would provide ideas for the design and development of highly selective catalysts for CO2 hydrogenation.

Enhanced H2 production at the atomic Ni–Ce interface following methanol steam reforming

“…Meanwhile, the KIE of D 2 O replaced by H 2 O was 1.35 ( k H / k D ∼ 1.35, Table 2) during the MSR reaction, which is smaller than that in the bare WGS test, suggesting a normal secondary isotopic effect. 67 This is also in good agreement with the assumption that the contribution of WGS to hydrogen formation under this differential reaction condition ( ca. 1 kPa CH 3 OH, 2 kPa H 2 O, Ar balanced, 623 K, GHSV = 19 099 h −1 ) is negligible.…”

“…As the adsorption of CO 2 is difficult from highly dispersed transition metals, we would suggest that the coverage of CO 2 from the catalytic surface is negligible. 65–67 The H 2 formation rates increased with H 2 O pressure with the nearly first-order dependence ( r H 2 ∼ [H 2 O] 0.6 ), then H 2 O or –OH may not be the MASIs on the surface of catalysts. The CO 2 formation rates decreased with H 2 pressure with the nearly negative first-order dependence ( r CO 2 ∼ [H 2 ] −0.8 ), indicating that H 2 or its derivatives ( i.e.…”

Unlocking the potential of alkaline-earth metal active centers for nitrogen activation and ammonia synthesis: the role of s–d orbital synergy

“…To assess the thermodynamic stability, the formation energy ( E f ) was calculated with the following equation: 29 E f = E total − E sub − 2 E AE Here, E total and E sub represent the total energies of double S/Se defective TMD substrates with and without anchored AE metals, respectively. E AE denotes the energy per atom of the bulk of the AE metal.…”

“…[24][25][26][27] Owing to their distinctive geometric and electronic structures, 2D TM dichalcogenide (TMD) nanosheets, particularly MoS 2 , have proven to be exceptional substrates for the fabrication of atomically dispersed catalysts. [28][29][30][31] Advancements in experimental techniques have enabled the controlled creation of double S vacancies in MoS 2 . [32][33][34] Capitalizing on these double S vacancies, Jiang et al adeptly craed a bifunctional NiFe double-atom catalyst (DAC), which exhibited remarkable catalytic efficiency and steadfast durability in the context of acidic water electrolysis.…”

Deciphering orbital hybridization in heterogeneous catalysis

“…21 Taking the typical H as an example, the site-H bonding strength is usually as an index to evaluate the H-concerned reactions such as photocatalytic H 2 evolution, electrocatalytic H 2 evolution, and heterogeneous hydrogenation. [39][40][41] The widely researched defect-laden indium oxides (In 2 O 3−x (OH) y ) are typical frustrated Lewis pairs (FLPs), on which heterolytic dissociation of H 2 could easily proceed with the formation of In-OH þ 2 ⋯In-H − through s-s orbital coupling. 42 With the neighboring site substitution by Bi element over In 2 O 3−x (OH) y , such FLPs sites exhibit a simultaneous improvement both in the basicity and acidity.…”