Local probe investigation of electrocatalytic activity

Abstract

Investigation of electrocatalytic materials with scanning probe techniques (SECM, SICM, SECCM and AFM) for energy storage and conversion devices.

From NiMoO4 to γ-NiOOH: Detecting the Active Catalyst Phase by Time Resolved in Situ and Operando Raman Spectroscopy

“… 4 , 10 An interesting and carbon neutral method to generate hydrogen is sustainable water electrolysis, in which water is split into molecular oxygen and hydrogen with the use of renewable electricity. 11 By powering of this process with solar or wind energy, the obtained hydrogen is carbon dioxide neutral and fully renewable, neglecting the carbon footprint of the manufactured wind, solar, and electrolysis devices. 4 , 12 − 14 Not only is splitting water photochemically, electrochemically, or photoelectrochemically of high interest for hydrogen generation, but a similar approach can also be utilized for the reduction of carbon dioxide to different chemicals (carbon monoxide, methane, or smaller organic molecules) or the reduction of nitrogen to form ammonia in a carbon neutral process.…”

“…Climate change and anthropogenic global warming, caused by rising amount of greenhouse gases, are two of the most urgent challenges we are facing in the 21st century. , A net addition of CO 2 into the atmosphere, generated by burning fossil fuel, is a known contributor to the greenhouse effect. A transition to renewable fossil free or carbon neutral fuels is therefore highly desired and urgent. − Rising effort is made to store renewable energy in chemical bonds where hydrogen, with its high gravimetric energy density, is a very promising energy carrier. − Unfortunately, most of the hydrogen utilized today is produced by steam re-forming from methane, in which methane is transformed at high temperatures to hydrogen with an accompanying release of carbon dioxide. , An interesting and carbon neutral method to generate hydrogen is sustainable water electrolysis, in which water is split into molecular oxygen and hydrogen with the use of renewable electricity . By powering of this process with solar or wind energy, the obtained hydrogen is carbon dioxide neutral and fully renewable, neglecting the carbon footprint of the manufactured wind, solar, and electrolysis devices. ,− Not only is splitting water photochemically, electrochemically, or photoelectrochemically of high interest for hydrogen generation, but a similar approach can also be utilized for the reduction of carbon dioxide to different chemicals (carbon monoxide, methane, or smaller organic molecules) or the reduction of nitrogen to form ammonia in a carbon neutral process. ,− The formation of hydrogen, carbon monoxide, methane, organic molecules, or ammonia from N 2 is done via reduction of their starting products and is thus taking place at the cathode of the electrochemical cell.…”

Unraveling the Link between Catalytic Activity and Agglomeration State with Scanning Electrochemical Microscopy and Atomic Force Microscopy

“…Another approach is using local probe techniques for studying a few amount of materials deposited on a substrate. Particularly, scanning electrochemical microscopy in redox competition mode (RC-SECM) is increasingly used for the local investigation of catalyst electroactivity. − This technique offers the advantage to study the material at a much lower loading than with classical voltammetry. For instance, loadings between 4 and 50 μg·cm –2 are investigated in this paper, while RDE studies of PGM-free materials usually consider loadings around 600 μg·cm –2 . , Working with low loadings enables to use less additives such as a binder and thus to access the intrinsic activity of the material.…”

High-resolution imaging of catalytic activity of a single graphene sheet using electrochemiluminescence microscopy

“…Electrocatalyst has attracted great interest on fundamental research, biomedicine, and energy conversion 1,2 . Currently, most characterizations of these electrocatalysts are performed at the ensemble level 2,3 .…”

“…Electrocatalysts have attracted great interest in fundamental research, biomedicine, and energy conversion. 1,2 Currently, most characterization studies of these electrocatalysts are performed at the ensemble level. 2,3 However, their structure, composition and electrical contact are intrinsically heterogeneous among different individuals, which impede the comprehensive understanding of their structure–activity correlation.…”