Catalyst Formation and In Operando Monitoring of the Electrocatalytic Activity in Flow Reactors

Abstract

Flow reactors are of increasing importance and have become crucial devices due to their wide application in chemical synthesis, electrochemical hydrogen evolution reaction (HER), or electrochemical waste water treatment. In many of these applications, catalyst materials such as transition-metal chalcogenides (TMCs) for the HER, provide the desired electrochemical reactivity for the HER. Generally, the flow electrolyzers' performance is evaluated as the overall output, but the decrease in activity of the electrolyzer is due to localized failure of the catalyst. Herein, we present a method for the spatially resolved (tens of micrometers) In Operando analysis of the catalytic activity under real operation conditions as well as the localized deposition of the catalyst in an operating model flow reactor. For these purposes, scanning electrochemical microscopy was applied for MoS x catalyst deposition and for localized tracking of the TMC activity with a resolution of 25 μm. This approach offers detailed information about the catalytic performance and should find broad application for the characterization and optimization of flow reactor catalysis under real operational conditions.

Operando Scanning Electrochemical Probe Microscopy during Electrocatalysis

“…Results were found to be consistent despite variations in electrolytes and sample dimensions. 485 The same SG-TC strategy with a Pt SECM tip to oxidize the evolved hydrogen was used to study the HER activity at a MoS x catalyst in a flow cell under flow and stationary conditions, 489 individual Au NPs (on HOPG/ polyphenylene), 490 in situ growth of NiCoP grains on Ti 3 C 2 T x MXenes (NiCoP@MXene) supported on HOPG, 491 and active-metal frameworks (Al 2 (OH) 2 -TCPP and Cu-based MOF HKUST-1). 492 Kund and co-workers fabricated a Pd-modified dealloyed Au−Ni microelectrode tip, which they used for the detection of H 2 under operando conditions at a Pt UME substrate during HER.…”

Recent Advances in the Glass Pipet: from Fundament to Applications

“…SECM Probe for Electrochemical Analysis of Inorganic Samples. In the recent two years, the SECM probe was also widely applied for numerous catalytic reactions, including oxygen reduction reaction (ORR), 112 oxygen evolution reaction (OER), 32 hydrogen evolution reaction (HER), 33 hydrogen oxidation reaction (HOR), 113 nitrate reduction reaction (NitRR), 114 and CO 2 reduction reaction (CO 2 RR). 115 Kosaka et al 116 applied operando detection integrated with a SECM microelectrode to determine the absolute OER rate on a highly efficient SrTiO 3 photocatalyst film immersed in a nitrogen-purged KCl solution.…”

“…Also, a nanopipette as a probe of SICM allows to noncontact visualize the topography of complex biological samples such as neuros and 3D cells, , to quantitatively analyze the ionic environment of bacteria and living cells, , and to explore mechanical properties , of cells related to cancer diagnosis with high spatial resolution. Moreover, a nanopipette also exhibits remarkable applications in SECM and SECCM for analysis of numerous catalytic reactions, for example, hydrogen/oxygen evolution reaction, , of inorganic and biological samples. Furthermore, utilizing the functionalized nanopipette with a nanoelectrode sensor is capable of insight into the redox process in the cell level …”

High performance multi-purpose nanostructured thin films by inkjet printing: Au micro-electrodes and SERS substrates

“…Nowadays, smart surfaces based on innovative thin lms are ubiquitous, spanning from standard electronic devices to the most ground-breaking developments on transistors, 1,2 energy harvesting, 3,4 sensors, 5 and catalysts. [6][7][8] Nonetheless, the majority of promising lab-scaled technologies have oen encountered difficulties in attracting industrial investments, due to their poor compliance with a high throughput. For instance, lithography is a benchmark in terms of manufacturing processing, but it relies on the use of hazardous and/or expensive materials, such as photoresists, which cannot be dened as environment friendly.…”