A transparent Pyrex μ-reactor for combined in situ optical characterization and photocatalytic reactivity measurements

Abstract

A new Pyrex-based μ-reactor for photocatalytic and optical characterization experiments is presented. The reactor chamber and gas channels are microfabricated in a thin poly-silicon coated Pyrex chip that is sealed with a Pyrex lid by anodic bonding. The device is transparent to light in the UV-vis-near infrared range of wavelengths (photon energies between ∼0.4 and ∼4.1 eV). The absorbance of a photocatalytic film obtained with a light transmission measurement during a photocatalytic reaction is presented as a proof of concept of a photocatalytic reactivity measurement combined with in situ optical characterization. Diffuse reflectance measurements of highly scattering photocatalytic nanopowders in a sealed Pyrex μ-reactor are also possible using an integrating sphere as shown in this work. These experiments prove that a photocatalyst can be characterized with optical techniques after a photocatalytic reaction without removing the material from the reactor. The catalyst deposited in the cylindrical reactor chamber can be illuminated from both top and bottom sides and an example of application of top and bottom illumination is presented.

Photocatalytic Hydrogen Production under Water Vapor Feeding─A Minireview

“…(b) Cross-section view of a transparent Pyrex μ reactor. These panels were reproduced with permission from ref . Copyright 2013 AIP Publishing.…”

Enabling real-time detection of photocatalytic reactions by a re-useable micro-reactor

“…Despite the above mentioned numerous advantages, the traditional design of our microreactors for photocatalysis makes it necessary to seal the reactor with anodic bonding. While it is possible to perform in-situ spectroscopical analysis of the catalyst and open the reactor after reaction for post reaction characterization, the microreactor cannot be re-used after opening the lid [12]. This restriction makes the traditional microreactors single use, i.e.…”

Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalysts—Enabling correlative characterization techniques

“…12 To date, such microreactors have rarely been applied for spectroscopic studies in heterogeneous catalysis. 11,[13][14][15][16][17] This is despite numerous advantages including good heat and mass transport properties, rapid heating/cooling, and allowing potentially higher pressures. In addition, due to the possibility to fabricate thin walls in one or two directions, they allow monitoring of reactions in situ (under controlled atmosphere) or operando (during working conditions).…”