Selective increase in CO ₂ electroreduction activity at grain-boundary surface terminations

Abstract

Altering a material's catalytic properties requires identifying structural features that give rise to active surfaces. Grain boundaries create strained regions in polycrystalline materials by stabilizing dislocations and may provide a way to create high-energy surfaces for catalysis that are kinetically trapped. Although grain-boundary density has previously been correlated with catalytic activity for some reactions, direct evidence that grain boundaries create surfaces with enhanced activity is lacking. We used a combination of bulk electrochemical measurements and scanning electrochemical cell microscopy with submicrometer resolution to show that grain-boundary surface terminations in gold electrodes are more active than grain surfaces for electrochemical carbon dioxide (CO) reduction to carbon monoxide (CO) but not for the competing hydrogen (H) evolution reaction. The catalytic footprint of the grain boundary is commensurate with its dislocation-induced strain field, providing a strategy for broader exploitation of grain-boundary effects in heterogeneous catalysis.

Efficient Electrochemical Reduction of CO2 to HCOOH over Sub‐2 nm SnO2 Quantum Wires with Exposed Grain Boundaries

“…[11] Although numerous materials, including nanostructured metals (for example,A u [12,13] and Ag [14,15] ), oxides (CuO [8] /Cu 2 O, [16] and ZnO [17] ), and chalcogenides (WSe 2 [18] /MoSe 2 , [19] and Ag 2 S [20] )h ave previously been used to promote CO 2 RR with enhanced performance toward various desired fuels,Sn-based materials are potentially more selective for HCOOH formation through tuning the particle size,m orphology,a nd composition. [25,26] Kanansgroup has studied the GB effect for CO 2 RR toward CO formation on flat, polycrystalline Au wires,with large grain size of about 200 mm. [25,26] Kanansgroup has studied the GB effect for CO 2 RR toward CO formation on flat, polycrystalline Au wires,with large grain size of about 200 mm.…”

“…[21][22][23][24] Besides,c omputational studies have suggested that the broken local spatial symmetry adjacent to the grain boundary (GB) can alter the binding energies of reaction intermediates,and consequently accelerate CO 2 RR toward CO formation. [26] However,i ts till remains very challenging to explicitly clarify the correlation between GBs and the enhanced reactivity in nanostructured materials with small dimension (for example,b elow 10 nm). [26] However,i ts till remains very challenging to explicitly clarify the correlation between GBs and the enhanced reactivity in nanostructured materials with small dimension (for example,b elow 10 nm).…”

Abundant Ce3+ Ions in Au‐CeOx Nanosheets to Enhance CO2 Electroreduction Performance

“…CO part current density shows largest for AuCe‐47.3 (Figure c), which is 2.5 fold higher than that of AuCe‐33.2 at −0.6 V. The B doping is rather low, which is less than 0.2 at% determined by ICP‐AES, so the B doping effect is excluded. To quantify the Ce 3+ effect, the CO FEs at −0.5 V (Figure d) are picked up to compare the activity, for Ce 3+ effect could be clearly quantified at a low overpotential to minimize the ordinary Au‐CeO x CO 2 ER activity . The CO FE is clearly enhanced monotonically as the Ce 3+ concentration increases, and the CO FE shows linear relation with Ce 3+ concentration.…”

Die lokale Oberflächenstruktur und ‐zusammensetzung bestimmt die Wasserstoffentwicklung an Eisen‐Nickelsulfiden

“…[20][21][22][23][24] Die besonderen Vorteile dieser Te chnik wurden jüngst am Beispiel des Materials MoS 2 [8,25] demonstriert. B. Fe 4.5 Ni 4.5 S 8 )g emittelt über die untersuchte Elektrodenoberfläche angegeben werden kann.…”