Operando monitoring of temperature and active species at the single catalyst particle level

A Theoretical Framework for Ratiometric Single Ion Luminescent Thermometers—Thermodynamic and Kinetic Guidelines for Optimized Performance

“…Er 3+ and Yb 3+ is the traditional lanthanide couple for upconversion-based in vivo imaging, [125][126][127][128][129][130][131][132][133] or in situ temperature monitoring of catalytic reactions or flow reactions in microfluidic devices. [85,86,[134][135][136][137][138] Recently reported creative alternatives of the use of this upconversion couple were vacuum sensing [139] or photothermal conversion. [140] Finally, Sm 3+ , [141,142] Eu 3+ , [135,[143][144][145][146] Dy 3+ [147][148][149][150][151][152][153] or Ho 3+ [154][155][156][157] show potential for thermometry far above room temperature, as was also reviewed by Chambers and Clarke.…”

A Ho3+‐Based Luminescent Thermometer for Sensitive Sensing over a Wide Temperature Range

“…In many research fields, ranging from cell biology to catalysis, the size and invasiveness of conventional thermometers hinders accurate temperature sensing. [1,2] Remote temperature sensing based such "Boltzmann thermometers" follows a simple analytical dependence on temperature of S r = ΔE/k B T 2 , where ΔE is the energy separation between the coupled states. This relation reveals a fundamental limitation of the Boltzmann thermometer: they offer low relative sensitivities at high temperatures (k B T > ΔE) because the Boltzmann populations of the two coupled states are nearly equal.…”

“…In many research fields, ranging from cell biology to catalysis, the size and invasiveness of conventional thermometers hinders accurate temperature sensing. [ 1,2 ] Remote temperature sensing based on luminescence thermometry offers an alternative that is capable of measuring heat generation and diffusion on the microscopic scale. [ 3 ] Among the various choices of luminescent systems, [ 4–9 ] crystals doped with lanthanide (Ln 3+ ) ions represent a particularly promising class of luminescent thermometers, because their dimensions can be tuned from a few nanometers to several micrometers and their photoluminescence spectrum is sensitive to temperature.…”

Operando detection of single nanoparticle activity dynamics inside a model pore catalyst material

“…Ensemble averaging effectively denies access to the detailed understanding of how catalyst material structure and composition dictate activity and selectivity, and of how the dynamics of (surface) oxidation and transient structural changes induced locally by the reaction control catalyst function (1)(2)(3)(4). This has spurred the development of "single particle catalysis" and corresponding experimental techniques (1)(2)(3)(4)(5)(6)(7)(8)(9). However, despite substantial progress in this field, it remains unaddressed that, at the level of the individual nanoparticle, local conversion of reactants can lead to the formation of reactant concentration gradients.…”