Selective C−C Coupling by Spatially Confined Dimeric Metal Centers

Abstract

Direct conversion of carbon dioxide (CO2) to high-energy fuels and high-value chemicals is a fascinating sustainable strategy. For most of the current electrocatalysts for CO2 reduction, however, multi-carbon products are inhibited by large overpotentials and low selectivity. For practical applications, there remains a big gap of knowledge in proper manipulation of the C−C coupling process. Herein, we exploit dispersed 3d transition metal dimers as spatially confined dual reaction centers for selective reduction of CO2 to liquid fuels. Various nitrogenated holey carbon monolayers are shown to be promising templates to stabilize these metal dimers and dictate their electronic structures, allowing precise control of the catalytic activity and product selectivity. By comprehensive first-principles calculations, we screen the suitable transition metal dimers that universally have high activity for ethanol (C2H5OH). Furthermore, remarkable selectivity for C2H5OH against other C1 and C2 products is found for Fe2 dimer anchored on C2N monolayer. The correlation between the activity and d band center of the supported metal dimer as well as the role of electronic coupling between the metal dimer and the carbon substrates are thoroughly elucidated.

“More is Different:” Synergistic Effect and Structural Engineering in Double‐Atom Catalysts

“…However, owing to the complexity of the CO 2 RR mechanism and the multifarious reaction products, more experimental and theoretical studies are required. TM 2 @phthalocyanine Mn 2 @phthalocyanine CH 3 OH −0.84 2017 [123] TM 2 @C 2 N Cu 2 @C 2 N CH 4 /C 2 H 4 −0.23 (CH 4 )/−0.76 (C 2 H 4 ) 2018 [124] Ni 2 , Co 2 , NiCo@C 2 N NiCo@C 2 N CH 4 −0.23 2019 [125] TM 1 /TM 2 @C 2 N CuCr/CuMn@C 2 N CH 4 −0.37/−0.32 2020 [50] TM 1 /TM 2 @N 6 -C CuMn, NiMn, NiFe@N 6 -C CO ≈−0.43 (CuMn); ≈−0.45 (NiFe); ≈−0.65 (NiMn) 2020 [52c] Fe 2 @holey N-doped carbon monolayers Fe 2 @C 2 N C 2 H 5 OH −0.70 2020 [126] Fen@graphdiyne (n = 1-4) Fe 2 @graphdiyne CH 4 −0.29 2020 [127] www.afm-journal.de www.advancedsciencenews.com…”

Emerging Ultrahigh‐Density Single‐Atom Catalysts for Versatile Heterogeneous Catalysis Applications: Redefinition, Recent Progress, and Challenges

“…[ 52 ] The first‐principles calculations showed that the limiting two adjacent metal atoms in the vacancy of the carrier to form a synergetic active center can not only fix two CO 2 molecules at the same time, but also spatially limit the reaction path that is conducive to C–C coupling to form C2 or C2+ high‐valued chemical products. [ 159 ] Analogously, the synergistic effects by interactions of adjacent sites also apply to the before‐mentioned ultrahigh‐density SACs, [ 30,84 ] where their synergistic sites are highly dense and omnidirectional on support, thus leading to better catalytic properties in heterogeneous catalysis.…”

Quantum Mechanical Screening of 2D MBenes for the Electroreduction of CO2 to C1 Hydrocarbon Fuels

“…The electron accumulation and depletion regions are represented in different colors in Figure c. The charge transfer to CO 2 from the MBene surface and the electron transfer from transition metal to boron further contribute to the stability of the adsorption configurations. , For the M 3 B 4 -type MBene substrate, the favorable adsorption site is on top of the metal atom with adsorption energies of −0.06 eV, −0.25 eV, and −0.05 eV, corresponding to Nb 3 B 4 , Ta 3 B 4 , and V 3 B 4 , respectively. Furthermore, for Hf 2 B 2 and Zr 2 B 2 , the sites of boron also provide an energetically preferred adsorption energy for CO 2 reduction.…”