Surface Ligand Promotion of Carbon Dioxide Reduction through Stabilizing Chemisorbed Reactive Intermediates

Abstract

We have explored functionalizing metal catalysts with surface ligands as an approach to facilitate electrochemical carbon dioxide reduction reaction (CORR). To provide a molecular level understanding of the mechanism by which this enhancement occurs, we combine in situ spectroscopy analysis with an interpretation based on quantum mechanics (QM) calculations. We find that a surface ligand can play a critical role in stabilizing the chemisorbed CO, which facilitates CO activation and leads to a 0.3 V decrease in the overpotential for carbon monoxide (CO) formation. Moreover, the presence of the surface ligand leads to nearly exclusive CO production. At -0.6 V (versus reversible hydrogen electrode, RHE), CO is the only significant product with a faradic efficiency of 93% and a current density of 1.9 mA cm. This improvement corresponds to 53-fold enhancement in turnover frequency compared with the Ag nanoparticles (NPs) without surface ligands.

Tuning Gold Nanoparticles with Chelating Ligands for Highly Efficient Electrocatalytic CO2 Reduction

“…The decreased intensities of signal peaks are likely resultant from the detachment of the non-covalently surface coated porphyrins (either physically adsorbed porphyrins or stacking of the porphyrins via p-p interactions) or blockage of the surface sites by residual electrolytes.F urthermore,t he electrochemically accessible Au surface area of P1-AuNP electrode before and after electrolysis is also similar as evidenced by the comparable peak areas of Au (111) and (110) in the UPD studies ( Supporting Information, Figure S9). Finally,improved durability of the catalytic interface has been confirmed by the consecutive voltammetry study [43] under CO 2 atmosphere,w hich showed that the CV curves nearly coincide after 10 consecutive cycles (Supporting Information, Figure S10).…”

“…Both N1sa nd S2p signals are quite consistent with prior features according to the XPS studies (Supporting Information, Figure S8). Finally,improved durability of the catalytic interface has been confirmed by the consecutive voltammetry study [43] under CO 2 atmosphere,w hich showed that the CV curves nearly coincide after 10 consecutive cycles (Supporting Information, Figure S10). Finally,improved durability of the catalytic interface has been confirmed by the consecutive voltammetry study [43] under CO 2 atmosphere,w hich showed that the CV curves nearly coincide after 10 consecutive cycles (Supporting Information, Figure S10).…”

Molecular tunability of surface-functionalized metal nanocrystals for selective electrochemical CO2 reduction

“…[18][19][20] Recently, the positive role of functional ligands in heterogeneous CO 2 RR electrocatalysis is emerging as a means to modify the reactivity of metallic surfaces. [21][22][23][24][25][26][27][28] Yet, there remains great space to tune the organic component in order to address unanswered questions. In particular, it is unclear the extent to which the functional groups that bind to the metal surface (i.e.…”

Tuning Gold Nanoparticles with Chelating Ligands for Highly Efficient Electrocatalytic CO2 Reduction

“…Furthermore, the electrochemically accessible Au surface area of P1‐AuNP electrode before and after electrolysis is also similar as evidenced by the comparable peak areas of Au (111) and (110) in the UPD studies (Supporting Information, Figure S9). Finally, improved durability of the catalytic interface has been confirmed by the consecutive voltammetry study under CO 2 atmosphere, which showed that the CV curves nearly coincide after 10 consecutive cycles (Supporting Information, Figure S10).…”