Gaia Neri

Photochemical CO2 reduction in water using a co-immobilised nickel catalyst and a visible light sensitiser

A dye-sensitised CO2 reduction photocatalyst that operates in water is reported. Transient spectroscopy demonstrates that the facile co-immobilisation of a Ru dye and a Ni CO2 reduction electrocatalyst enables efficient on-particle electron transfer leading to photocatalytic activity that greatly exceeds the equivalent solution based system.

The Role of Electrode–Catalyst Interactions in Enabling Efficient CO2 Reduction with Mo(bpy)(CO)4 As Revealed by Vibrational Sum-Frequency Generation Spectroscopy

Group 6 metal carbonyl complexes ([M(bpy)(CO)4], M = Cr, Mo, W) are potentially promising CO2 reduction electrocatalysts. However, catalytic activity onsets at prohibitively negative potentials and is highly dependent on the nature of the working electrode. Here we report in situ vibrational SFG (VSFG) measurements of the electrocatalyst [Mo(bpy)(CO)4] at platinum and gold electrodes. The greatly improved onset potential for electrocatalytic CO2 reduction at gold electrodes is due to the formation of the catalytically active species [Mo(bpy)(CO)3]2- via a second pathway at more positive potentials, likely avoiding the need for the generation of [Mo(bpy)(CO)4]2-. VSFG studies demonstrate that the strength of the interaction between initially generated [Mo(bpy)(CO)4]•- and the electrode is critical in enabling the formation of the active catalyst via the low energy pathway. By careful control of electrode material, solvent and electrolyte salt, it should therefore be possible to attain levels of activity with group 6 complexes equivalent to their much more widely studied group 7 analogues.

Raw Data supporting article: ZnSe qantum dots modified with a Ni(cylam) catalyst for efficient visible-light driven CO2 reduction in water

Raw Data supporting article: ZnSe qantum dots modified with a Ni(cylam) catalyst for efficient visible-light driven CO2 reduction in water

Detection of catalytic intermediates at an electrode surface during carbon dioxide reduction by an earth-abundant catalyst

The electrocatalytic reduction of CO2 offers a sustainable route to the many carbon fuels and feedstocks that society relies on. [fac-Mn(bpy)(CO)3Br] (bpy, 2,2-bipyridine) is one of the most promising and intensely studied CO2 reduction electrocatalysts. However, the catalytic mechanism remains experimentally unproven and many key intermediates of the prototypical catalyst have not been observed. Here we report the use of vibrational sum-frequency generation spectroscopy to study the catalytic intermediates during CO2 reduction in situ at the electrode surface. We explore the complex applied-potential and acid-dependent mechanistic pathways and provide evidence of the theoretically derived mechanisms. Demonstrating the ability to detect the key species that are only transiently present at the electrode surface is important as the need for an improved mechanistic understanding is a common theme throughout the field of molecular electrocatalysis.Manganese carbonyl complexes are promising electrocatalysts for CO2 reduction, but the intricate mechanisms are difficult to probe. Here, vibrational sum-frequency generation spectroscopy is used to detect the transient catalytic intermediates, providing experimental evidence for the mechanism and demonstrating the utility of the analytical approach for molecular electrocatalytic processes in general.