Screening of the Transition Metal Single Atom Anchored on α-Borophene Catalysts as a Feasible Strategy for Electrosynthesis of Urea

Abstract

Theoretical study of the electrochemical CO2 reduction reaction (CO2RR) and N2 reduction reaction synergistic synthesis of urea via C–N bond coupling, which has provided a high-efficiency approach to developing renewable energy conversion and storage, could also play a significant role in reducing carbon dioxide emissions. However, the practical design and development of electrocatalysts with high activity and selectivity for urea exhibits remain many challenges. Herein, building up a screening strategy based on density functional theory calculations on the transition metal single atom anchored on α-borophene nanosheets provided a route for systematically exploring catalytic activity and electronic properties of the catalyst during CO2 and N2 electroreduction. M@α-B (Ti, Cr, Nb, Mo, and Ta) exhibits promising catalytic activity and selectivity toward the production of urea with the working potentials of −0.31, −0.16, −0.32, and −0.31 V, respectively, during the electrochemical reaction process. Furthermore, the superior activity is closely related to the d-band center and the charge density transfer of active center atoms. To gain insights into the intrinsic correlation between the binding and structural properties, the d-band center position of these M@α-B materials and the limiting potential are used to estimate the catalytic activity of catalysts. Thus, a volcano plot has established a base on the limiting potential with the d-band center positions, and a new descriptor (φ) is suggested to gain insights into the intrinsic correlation from the viewpoint of atomic properties, which involves the electronegativity and the number of d orbital electrons (N d) of metal atoms. Therefore, a moderate limiting potential (−0.4 < U L < 0 V) and d-band center (−0.2 < ?d < 0.8 eV) lead to high catalytic activity and both thermodynamic and electronic properties of materials. The theoretical landscape for screening M@α-B toward CO2 and N2 conversion into urea will provide a practical approach to gaining insights into the electrochemical reaction mechanism for urea synthesis. It also motivates the experimental efforts to explore the electrocatalysts for other electrochemical reactions.

Unique Geometrical and Electronic Properties of TM2B2 Quadruple Active Sites Supported on C2N Monolayer Toward Effective Electrochemical Urea Production

“…Generally, the activity for urea production is determined by two potential PDSs, i.e., * N 2 + COOH + H + + e − → * N 2 + CO + H 2 O or * NHCONH 2 + H + + e − → * NH 2 CONH 2 . [ 46,52,53 ] For simplification, the free energy changes of these two steps were calculated by using the CHE model, which has been extensively used in the computational catalysis as it can accurately capture the essence of catalysis. [ 12,49,54–56 ] Since the co‐adsorption configuration of CO 2 and N 2 determines the selectivity toward urea production, we tentatively use its co‐adsorption free energy ($$\Delta {G_{*{{\rm{N}}_2} + {\rm{C}}{{\rm{O}}_2}}}$$) as a descriptor to explore the activity origin.…”

“…To get a deep insight into the activity origin of Cr 2 B 2 @C 2 N, all the stable TM 2 B 2 @C 2 N were considered as the potential electrocatalyst toward urea synthesis. Generally, the activity for urea production is determined by two potential PDSs, i.e., * N 2 [46,52,53] For simplification, the free energy changes of these two steps were calculated by using the CHE model, which has been extensively used in the computational catalysis as it can accurately capture the essence of catalysis. [12,49,[54][55][56] Since the co-adsorption configuration of CO 2 and N 2 determines the selectivity toward urea production, we tentatively use its co-adsorption free energy ( G *N CO ∆ + is ≈−0.89 eV, at which the best activity can be achieved.…”

Screening of Transition Metal Supported on Black Phosphorus as Electrocatalysts for CO2 Reduction

“…Two-dimensional (2D) materials have been widely used to stabilize metal atoms. 26,27 Particularly, black phosphorus (BP) has been attracting significant attention as a promising 2D material in recent years. 28−30 BP is a black crystal exhibiting a metallic luster.…”

Comprehensive Study Addressing the Challenge of Efficient Electrocatalytic Biomass Upgrading of 5‐(Hydroxymethyl)Furfural (HMF) with a CH3NH2 Ionic Liquid on Metal‐Embedded Mo2B2 MBene Nanosheets

“…Furthermore, owing to the good conductivities and large specific areas of MBenes, metals embedded on Mo 2 B 2 MBene as SACs are worth investigating. [32,33] We systematically studied SACs comprising TM atoms embedded in the Mo vacancies of Mo 2 B 2 MBenes to study the electrocatalytic biomass upgrading of HMF via reductive amination using first-principles calculations. Having excellent structural stabilities and conductivities, the Mo 2 B 2 @Cr, Mo 2 B 2 @Zr, Mo 2 B 2 @Nb, Mo 2 B 2 @Ru, Mo 2 B 2 @Rh, and Mo 2 B 2 @Os MBene systems were used as electrocatalysts for the reductive amination of HMF.…”

“…Furthermore, owing to the good conductivities and large specific areas of MBenes, metals embedded on Mo 2 B 2 MBene as SACs are worth investigating. [ 32,33 ]…”