Interatomic Electronegativity Offset Dictates Selectivity When Catalyzing the CO₂ Reduction Reaction

Abstract

overcome the thermodynamic and kinetic stability of CO 2 molecules. [9][10][11] Various products, including CO, formic acid, and C 2+ products, have been achieved. [12][13][14] However, their catalytic efficiency and product selectivity for practical application are still limited by the large overpotential and undesirable competition of the hydrogen evolution reaction (HER). [15][16][17][18] Therefore, it is urgent to accurately control electrocatalysts at the atomic scale to break the inherent scaling relationship for the CO 2 RR.Recently, transition metal single-atom catalysts (SACs) have attracted tremendous attention for the CO 2 RR due to their sufficient atom utilization efficiency and desirable electronic states. [19][20][21] Ni single atom (SA) supported on graphene demonstrates good performance for CO 2 reduction to CO; however, it also suffers from a high onset potential due to the weak binding strengths of the intermediates at the Ni-N-C sites, leading to a high energy barrier to form *COOH intermediates. [22,23] Fe SA exhibits a low onset potential for the CO 2 RR, but unfortunately, the strong binding of *CO at the Fe sites seriously lowers the Faraday efficiency (FE) and stability. [24][25][26][27] Therefore, balancing the adsorption strength for both *COOH and *CO intermediates on only one kind of single metal site is a great challenge. It has been reported that dual-single-atom (DSA) catalysts with substantially different coordination environments and quantum size effects have the potential to surpass the well-established SACs for the CO 2 RR. [28][29][30][31][32] However, insufficient theory-designed DSA catalysts impede the development of DSA catalysts with specific catalytic activity. [31] Furthermore, the understanding regarding the mechanism for the enhanced catalytic process lacks in-depth research both experimentally and theoretically. [32] Most of the reported DACs have primarily focused on the thermodynamic pathway, for example, the Gibbs free energy, while the electron interactions between dual atoms and the kinetic pathway are equally indispensable for obtaining a thorough comprehension of this enhanced CO 2 RR process. [33][34][35][36][37] Therefore, the rational design of high-performance DSA remains conceptually challenging, and the electronic variation of each metal site during the CO 2 RR process has yet to be explored.Herein, we design a DSA catalyst consisting of atomically dispersed Cu and Ni bimetal sites, and the electronegativity offset between the Cu and neighboring Ni atoms significantly Achieving efficient efficiency and selectivity for the electroreduction of CO 2 to value-added feedstocks has been challenging, due to the thermodynamic stability of CO 2 molecules and the competing hydrogen evolution reaction. Herein, a dual-single-atom catalyst consisting of atomically dispersed CuN 4 and NiN 4 bimetal sites is synthesized with electrospun carbon nanofibers (CuNi-DSA/CNFs). Theoretical and experimental studies reveal the strong electron interactions induced by the electro...

Facile synthesis of a novel 0D/2D CdS/Bi4TaO8Br heterojunction for enhanced photocatalytic tetracycline hydrochloride degradation under visible light

“…6d). 45,46 The electron spin resonance (ESR) tests in Fig. 7a and b prove that the CdS/Bi 4 TaO 8 Br-200 photocatalyst can generate more O 2 À and OH than the pure Bi 4 TaO 8 Br sample.…”

Emerging dual-atomic-site catalysts for electrocatalytic CO2 reduction

“…The same coordination configuration of Cu-N 4 and Ni-N 4 in Ni-Cu DASCs was also constructed by the sequential electrospinning and chemical vapor deposition technologies [91]. The Ni-Cu DASCs displayed a notable FE CO of 99.6% at an operated potential of −0.98 V vs. RHE.…”

Multi-atom cluster catalysts for efficient electrocatalysis

“…Thus, the incorporation of more atoms to form multi-atom cluster catalysts may hold promise to either boost the performance of CO 2 RR or provide more catalytic reaction sites to facilitate complex reactions and produce CO, HCOOH, CH 4 , C 2 H 4 , etc., through effective interactions. 172,[229][230][231][232][233][234][235][236][237][238][239] It is well known that the transition metals can exhibit varied interaction strength with the intermediates due to their electronic features. Thus, the inclusion of a hetero-atom can help tune the activity through the tuning of the interaction strength with intermediates.…”