Scanning electrochemical microscopy screening of CO2 electroreduction activities and product selectivities of catalyst arrays

Abstract

The electroreduction of CO2 is one of the most investigated reactions and involves testing a large number and variety of catalysts. The majority of experimental electrocatalysis studies use conventional one-sample-at-a-time methods without providing spatially resolved catalytic activity information. Herein, we present the application of scanning electrochemical microscopy (SECM) for simultaneous screening of different catalysts forming an array. We demonstrate the potential of this method for electrocatalytic assessment of an array consisting of three Sn/SnOx catalysts for CO2 reduction to formate (CO2RF). Simultaneous SECM scans with fast scan (1 V s−1) cyclic voltammetry detection of products (HCOO−, CO and H2) at the Pt ultramicroelectrode tip were performed. We were able to consistently distinguish the electrocatalytic activities of the three compositionally and morphologically different Sn/SnOx catalysts. Further development of this technique for larger catalyst arrays and matrices coupled with machine learning based algorithms could greatly accelerate the CO2 electroreduction catalyst discovery.

Continuous electroconversion of CO2 into formate using 2 nm tin oxide nanoparticles

“…In particular, a lot of attention has been focused on identifying the role of the different species present on the surface of the electrode (Sn/SnO/SnO 2 ) during CO 2 RR. This surface composition-reactivity relationship has been studied in detail by Raman and IR spectroscopy [48][49][50] and scanning electrochemical microscopy (SECM) [51], which have demonstrated that oxide films (SnO x ) on the surface of Sn electrodes play a key role by enhancing formate production and selectivity during CO 2 RR.…”

2D SnSe Cathode Catalyst Featuring an Efficient Facet‐Dependent Selective Li2O2 Growth/Decomposition for Li–Oxygen Batteries

“…Peaks centered at 486.4 and 494.8 eV are attributed to Sn-Se bonding, and those peaks at 487.2 and 495.6 eV can be assigned to the Sn 4+ state in SnO 2 , resulting from surface oxidation. [44][45][46][47] By fitting the curve in Figure 1f, the atomic ratio of Sn 2+ /Sn 4+ is obtained, with a value of 7:3. Meanwhile, in the high-resolution XPS spectrum of Se in Figure 1g, peaks at 53.8 and 54.7 eV can be assigned to Se 3d 5/2 and 3d 3/2 of Se 2− valence states.…”

Progress and Challenges of Carbon Dioxide Reduction Reaction on Transition Metal Based Electrocatalysts

“…62 To analyze the effect of pre-electroreduction and roughness factor on SnO x catalysts, Mayer et al performed scanning electrochemical microscopy (SECM) analyses on three differently synthesized catalysts. 63 They applied preelectroreduction potential to the tin catalysts of −1.25 and −3 V vs Ag/AgCl (V) and observed the corresponding changes on the catalyst surface. When −1.25 V vs Ag/AgCl potential was applied, the Sn 2+ and Sn 1+ reduced to Sn 0 which then oxidized with atmospheric oxygen species to create SnO 2 surface defects.…”