A Heteroleptic Gold Hydride Nanocluster for Efficient and Selective Electrocatalytic Reduction of CO₂ to CO

Abstract

It has been a long-standing challenge to create and identify the active sites of heterogeneous catalysts, because it is difficult to precisely control the interfacial chemistry at the molecular level. Here we report the synthesis and catalysis of a heteroleptic gold trihydride nanocluster, [Au22H3(dppe)3(PPh3)8]3+ [dppe = 1,2-bis­(diphenyl­phosphino)­ethane, PPh3 = triphenyl­phosphine]. The Au22H3 core consists of two Au11 units bonded via six uncoordinated Au sites. The three H atoms bridge the six uncoordinated Au atoms and are found to play a key role in catalyzing electrochemical reduction of CO2 to CO with a 92.7% Faradaic efficiency (FE) at −0.6 V (vs RHE) and high reaction activity (134 A/gAu mass activity). The CO current density and FECO remained nearly constant for the CO2 reduction reaction for more than 10 h, indicating remarkable stability of the Au22H3 catalyst. The Au22H3 catalytic performance is among the best Au-based catalysts reported thus far for electrochemical reduction of CO2. Density functional theory (DFT) calculations suggest that the hydride coordinated Au sites are the active centers, which facilitate the formation of the key *COOH intermediate.

Catalytic Conversion of CO2 over Atomically Precise Gold-Based Cluster Catalysts

“…43 Recently, Wang and co-workers reported a heteroleptic gold trihydride cluster, that is, [Au 22 H 3 (dppe) 3 (PPh 3 ) 8 ] 3+ (where dppe is 1,2-bis-(diphenylphosphino)ethane; short for Au 22 H 3 ) (Figure 5c). 44 By comparing the catalytic performances of the [Au 22 H 3 (dppe) 3 (PPh 3 ) 8 ] 3+ and [Au 11 (dppe) 5 ] 3+ (short for Au 11 ) for electrochemical reduction of CO 2 , the Au 22 H 3 cluster showed higher activity and higher FEco than the Au 11 with smaller size (Figure 5d). The extraordinary performance of the Au 22 H 3 cluster was determined by its unique atomic-packing structure.…”

“…Well-known gold clusters denoted as Au n L m , where L is the ligand and n and m refer to the number of gold atoms and ligands in a cluster, respectively, are typical of atomically precise metal clusters. Through a decade of efforts since the high-quality singe crystal of Au 102 (SR) 44 cluster was obtained and its total structure was successfully solved by SCXRD, atomically precise gold clusters with various structures have been available to the potential applications of optics, magnetics, sensing, imaging, and catalysis. 19−21 Notably, gold nanoparticles are important catalysts for various chemical reactions, but almost all of the current studies only give rise to an ensemble average of the catalytic performances because of the structural polydispersity and heterogeneity of gold nanoparticle catalysts.…”

Asymmetrically Doping a Platinum Atom into a Au38 Nanocluster for Changing the Electron Configuration and Reactivity in Electrocatalysis

“…Both geometric and electronic structures play crucial roles in determining the catalytic properties of nanoparticles [1–14] . However, the two factors are often convoluted, and it is thereby difficult to precisely study the contribution of one factor to the overall catalytic performance at a time.…”

Bicarbonate Rebalances the *COOH/*OCO– Dual Pathways in CO2 Electrocatalytic Reduction: In Situ Surface-Enhanced Raman Spectroscopic Evidence

“…The electrocatalytic reduction of carbon dioxide (CO 2 ER) to fuels and value-added chemicals has attracted attention for its great potential in realizing carbon neutralization to address global warming and the energy crisis. , Three main factors impact the CO 2 ER activity and selectivity: electrocatalyst, solid–liquid microinterface process, and choice of electrolyte. − The adsorption behaviors of intermediates on catalyst surface are closely associated with catalyst surface electronic properties. Through diverse innovative strategies of regulating elements or structures (e.g., alloying or nanostructure), the altered electronic structures of active sites can strengthen the binding of specific intermediates and thus promote the intrinsic activity and selectivity of electrocatalysts. − Meanwhile, the electron transfer, ion transport, and gas diffusion at the microinterface are pivotal in acquiring the high energy efficiency of CO 2 ER.…”