Multimethod Approach to the Low-Overpotential Region of Micro- to Macro-Scale Working Electrodes of Sub-10 nm Gold Nanoparticles in the CO Reduction Reaction.

The electrochemical carbon dioxide reduction reaction (CO2RR) over carbon-supported gold nanoparticles (AuNP) was investigated using a broad variety of (electro)analytical methods, including linear sweep voltammetry with a rotating disk electrode (LSV-RDE), sample-generation tip-collection mode of scanning electrochemical microscopy (SG/TC-SECM), as well as full cell tests with highly sensitive online gas chromatography (GC). In contrast to most other studies, this work focuses on the low-overpotential region (0 to -0.4 V vs RHE) where initial product formation is already detected and addresses micro- to macro-sized electrodes.

Quantifying the removal of stabilizing thiolates from gold nanoparticles on different carbon supports and the effect on their electrochemical properties.

Gold nanoparticles <10 nm in size are typically prepared using stabilizing agents, thiolates. Often standard recipes from literature are used to presumably remove these stabilisers to liberate the surface, for catalytic or electrocatalytic applications, however the success of these procedures is often not verified. In this work, thiolate-stabilised AuNPs of 2 nm in size were synthesized and supported onto three different carbon supports, resulting in loadings from 15 to 25 wt% Au.