Towards molecular understanding of local chemical environment effects in electro- and photocatalytic CO2 reduction

Imidazolium-modification enhances photocatalytic CO2 reduction on ZnSe quantum dots

“…After 10 h of continuous irradiation, a total of 0.64±0.11 mmol CO gZnSe −1 is produced with a modest CO-selectivity (defined as n CO / (n CO + n H2)) of < 3%. We confirmed the origin of generated CO from reduced CO2 by 13 C-isotopic labelling experiments (Figure S7) to exclude any contribution from decomposition of residual organic impurities or solvents. Encouraged by the ability of the QDs to reduce small amounts of CO2 even in the absence of any co-catalyst, we sought to enhance the performance by surface modification with an imidazolium moiety.…”

“…Only negligible amounts of CO are produced under N2 flow (Figure S11) and no gaseous products are detected in the dark or in the absence of QDs or AA, demonstrating that all components of the photocatalytic system are required (Table S2). 13 C-labelling also confirmed CO2 as the sole origin of CO in the presence of MEMI (Figure S7). To rule out the possibility that the influence of MEMI originates purely from the presence of a thiol group, we conducted a control experiment with a ligand consisting of a thiol with no additional functionality, 1-butanethiol (BuSH), which resulted in a similar product distribution compared to non-functionalized ZnSe (Figure S12).…”

“…12 The local chemical environment of CO2 reduction active sites is considered a key determinant in the design of efficient catalysts. 13 Imidazolium based ionic liquids (ILs) have been explored in numerous reports due to their influence on CO2 electroreduction although the mechanistic details still remain controversial. [14][15][16] In electrochemical CO2 reduction, early studies reported that the additive 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIM-BF4) in the electrolyte solution (18 mol%) with a Ag electrode stabilizes the * CO2  intermediate (where * denotes a surface active site) through complexation to effectively lower the initial activation barrier.…”

Modulating electron density of vacancy site by single Au atom for effective CO2 photoreduction

“…The above discussions suggest that the types of vacancies and the size of Au nanostructures present a different effect on the intermediates in the CO 2 adsorption process. In previous studies, reaction sites have possibly affected the generation of intermediates 46 vacancies (vacancy site) are selected to be the different CO 2 adsorption sites. The CO 2 adsorption models on Au/Cd 1−x S and Au/CdS 1−x are constructed by the DFT method (cf.…”

Operando spectroscopy of nanoscopic metal/covalent organic framework electrocatalysts

“…Finally, the pockets within the MOF/ COF framework can be functionalized to act in an enzymemimetic manner through secondary coordination sphere effects. 22,23 Here, the catalytic pockets stabilize intermediates, minimize reorganization energies and thermodynamically and/or kinetically direct the reaction to efficiently proceed solely through the desired pathway.…”