Single‐Unit‐Cell Catalysis of CO₂ Electroreduction over Sub‐1 nm Cu₉S₅ Nanowires

Abstract

As a bridge between nanocrystal catalysts and single‐atom catalysts, single‐unit‐cell catalysts seem at first glance to be unavailable for catalysis due to quantum effects and synthetic difficulties. Here, 24 nm Cu9S5 nanowires are synthesized via the LaMer pathway. Interestingly, when polyoxometalate (POM) clusters are introduced during the nucleation process, the 0.9 nm Cu9S5 nanowires are finally formed via covalent co‐assembly, analog to A–B–A–B‐type block co‐polymerization in the polymer field (“A” and “B” represent Cu9S5 unit cells and POM clusters, respectively). Multiple characterizations show that Cu9S5 exists as single‐unit‐cell structure. Therefore, each unit cell can work as an isolated active site. The single‐unit‐cell structure exhibits higher electrocatalytic activity and Faradaic efficiency (FE) of formic acid (82.0% at −0.8 V vs reversible hydrogen electrode (RHE)) during CO2 electroreduction, while the nanocrystal structure generates HCOO−, methanol, and ethanol with low FEs. This study suggests that the single‐unit‐cell catalyst displays great potential for precise catalysis by the finite size effect.

Recent progress of sub-1 nm nanomaterials: synthesis, polymer-analogue properties and applications in redox catalysis

“…We also obtained ''A-B-A-B'' type copolymer-analogue Cu 9 S 5 -PW 12 SNWs. 37 The construction of the showed an average width of 0.9 nm, which was consistent with the size of the Cu 9 S 5 clusters (8.93 Å). The results above demonstrated that the sizes of Cu 9 S 5 -PW 12 SNWs were at the single-unit scale.…”

“…At the microscopic scale, the GdOOH SNWs exhibited high flexibility. As the polarity of the dispersions increased, the GdOOH SNWs could coil themselves to form 37 This journal is © The Royal Society of Chemistry 2022 nanorings (Fig. 4(b)).…”

Recent Advances in Interface Engineering for Electrocatalytic CO2 Reduction Reaction

“…Recently, by introducing polyoxometalate (POM) cluster, Cu 9 S 5 single-unit-cell with sub-nanometer of 0.9 nm was prepared through modulating the nucleation pathway (Fig. 14 a) [ 262 ]. Thus, each unit Cu 9 S 5 cell can be regarded as molecular catalyst functioning as an isolated active site for CO 2 RR.…”

“…Reprinted with permission from Ref. [ 262 ]. d Schematic illustration of photosynthesis and photoelectrochemical reduction of CO 2 on chlorophyll and HNTM-Au-SA.…”

Manipulating Cu Nanoparticle Surface Oxidation States Tunes Catalytic Selectivity toward CH4 or C2+ Products in CO2 Electroreduction

“…By contrast, metallic Cu 0 dominated surfaces facilitate the selective production of CH 4 . Thus far, a large proportion of the relevant literature works have been focused on Cu precursors with specific single chemical states, such as copper oxide (CuO), [ 10 ] CuN, [ 11 ] CuS, [ 12 ] Cu(OH) 2 , [ 13 ] CuOHFCl, [ 14 ] and Cu‐MOFs. [ 15 ] However, controllable manipulation of the surface chemical state of Cu‐based catalysts to achieve multifunctionality with specificity for a particular type of product remains very challenging.…”