Bond-Making and Breaking between Carbon, Nitrogen, and Oxygen in Electrocatalysis

Abstract

Many catalytic reactions involving small molecules, which are key transformations in sustainable energy and chemistry, involve the making or breaking of a bond between carbon, nitrogen and oxygen. It has been observed that such heterogeneously (electro)catalyzed reactions often exhibit remarkable and unusual structure sensitivity, in the sense that they take place preferentially on catalyst surfaces with a long-ranged two-dimensional (100) atomic structure. Steps and defects in this two-dimensional structure lower the catalytic activity. Such structure sensitivity must be due to the existence of a special active site on these two-dimensional (100) terraces. Employing detailed density functional theory calculations, we report here the identification of this special active site for a variety of catalytic reactions. The calculations also illustrate how this specific site breaks the well-known rule that under-coordinated surface atoms bind adsorbates stronger, thereby providing the atomic-level explanation for the lack of reactivity of steps and defects for the reactions under consideration. The breakdown of such rule results in significant deviations from commonly observed energetic scaling relations between chemisorbates. Thus, this work provides new design rules for the development of thermodynamically efficient catalysts for an important class of bond-making and bond-breaking reactions.

Catalysts and Reaction Pathways for the Electrochemical Reduction of Carbon Dioxide

“…The C-C bond making by the reductive coupling of CO is somewhat similar to the reductive carbonyl coupling to olefins as originally suggested by McMurry. 38 Our DFT calculations have shown that the formation of the negatively-charged CO dimer is most stable on square arrangements of four surface atoms, 23 explaining the observed preferential formation of 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 11 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 ethylene on Cu(100) at low potentials. At this point i...…”

Subsurface Oxygen in Oxide-Derived Copper Electrocatalysts for Carbon Dioxide Reduction

“…47 Furthermore, it was shown that an increased local pH, caused by the consumption of protons in the pores of a rough catalyst, also promotes C-C-coupling. 17,18 However, studies which investigated those effects particularly for oxide-derived copper came to the conclusion, that neither the exposed facets 15 nor the increase in local pH 19 can sufficiently explain the extraordinary properties of these catalysts.…”

Atomistic Insights into Nitrogen-Cycle Electrochemistry: A Combined DFT and Kinetic Monte Carlo Analysis of NO Electrochemical Reduction on Pt(100)

“…First, it is often the case that bond formation, in this case N-N bonds, can occur with lower overbarriers on the square lattice of the (100) surface as compared to the hexagonal (111) surface. [33][34][35] Second, Duca and coworkers showed that N 2 is a product of nitrate reduction through the NO* intermediate on the Pt(100) surface in alkaline media. 36 Those authors also proposed that the structure sensitivity is critical for the formation of N 2 via reaction of NO*+NH 2 *.…”