A metal-supported single-atom catalytic site enables carbon dioxide hydrogenation

Abstract

Nitrogen-doped graphene-supported single atoms convert CO2 to CO, but fail to provide further hydrogenation to methane – a finding attributable to the weak adsorption of CO intermediates. To regulate the adsorption energy, here we investigate the metal-supported single atoms to enable CO2 hydrogenation. We find a copper-supported iron-single-atom catalyst producing a high-rate methane. Density functional theory calculations and in-situ Raman spectroscopy show that the iron atoms attract surrounding intermediates and carry out hydrogenation to generate methane. The catalyst is realized by assembling iron phthalocyanine on the copper surface, followed by in-situ formation of single iron atoms during electrocatalysis, identified using operando X-ray absorption spectroscopy. The copper-supported iron-single-atom catalyst exhibits a CO2-to-methane Faradaic efficiency of 64% and a partial current density of 128 mA cm−2, while the nitrogen-doped graphene-supported one produces only CO. The activity is 32 times higher than a pristine copper under the same conditions of electrolyte and bias.

“Sabatier principle” of d electron number for describing the nitrogen reduction reaction performance of single-atom alloy catalysts

“…Experimentally, several Cu-based SAA catalysts doped with TMs from the VIIIB group have been successfully synthesized. [41][42][43][44][45] However, there are greater spaces of SAAs through doping TMs from other elements. In this work, we built the theoretical models of Cu-based SAA catalysts using 18 TMs from the VB to VIIIB groups (3d: V, Cr, Mn, Fe, Co, Ni; 4d: Nb, Mo, Tc, Ru, Rh, Pd; 5d: Ta, W, Re, Os, Ir, Pt), as shown in Fig.…”

Single Atom Catalysts: An Overview of the Coordination and Interactions with Metallic Supports

“…The concept of single atom catalysts (SACs) was first introduced by Zhang and coworkers in 2011, where a single atomic layer of platinum was incorporated into an iron oxide support. [4] Since then, SACs have been utilized to catalyse several reactions such as water oxidation, [5][6][7] CO 2 reduction [8][9][10] and hydrogenation, [11,12] oxygen reduction, [13][14][15] hydrogen evolution, [7,[15][16][17][18] among others. [7,[19][20][21][22][23] Zhang and co-workers also synthesized a mixed gold and palladium SAC, which was supported on ion exchange resins and used to catalyse Ullmann reaction [24] of aryl halides in an aqueous media.…”

Optimizing Atomically Dispersed Metal Electrocatalysts for Hydrogen Evolution: Chemical Coordination Effect and Electronic Metal Support Interaction

“…On the other hand, carbon materials as substrates not only provide anchor points for single metal atoms, but also change the charge density and electronic structure of metal atoms due to the strong interface interaction between metal atoms and adjacent carbon atoms [18] . New electronic metal‐support interaction is involved when the carbon materials with metal atoms introduced act as substrates to support metal nanocrystals, which enhancing the stability of the catalyst in the HER reaction while ensuring the activity of the catalyst [19] . This metal support interaction (MSI) is the focus of metal carbon‐based catalysts in recent years, and studies have found that when the size of metal nanoparticles is reduced to the single atom level, the MSI will be maximized, resulting in new catalytic active sites and finally improve the catalytic performance [20] …”

“…[18] New electronic metal-support interaction is involved when the carbon materials with metal atoms introduced act as substrates to support metal nanocrystals, which enhancing the stability of the catalyst in the HER reaction while ensuring the activity of the catalyst. [19] This metal support interaction (MSI) is the focus of metal carbon-based catalysts in recent years, and studies have found that when the size of metal nanoparticles is reduced to the single atom level, the MSI will be maximized, resulting in new catalytic active sites and finally improve the catalytic performance. [20] Importantly, a significant advantage of atomically dispersed metal carbon-based catalysts is that the structurally uniform and well-defined single atomic site is an ideal model system for providing atomic-level insight into active sites and the corresponding catalytic reaction mechanism.…”