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A UV‐LEDs based photomicroreactor for mechanistic insights and kinetic studies in the norbornadiene photoisomerization
Author(s) -
Shen Chong,
Shang Minjing,
Zhang Hong,
Su Yuanhai
Publication year - 2020
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.16841
Subject(s) - norbornadiene , photoisomerization , chemistry , light emitting diode , photochemistry , mercury vapor lamp , microreactor , kinetic energy , optoelectronics , isomerization , materials science , organic chemistry , physics , quantum mechanics , catalysis
In this work, we report a simple and inexpensive UV‐LEDs based photomicroreactor assembly constructed by commercially available components. The photoisomerization of norbornadiene to quadricyclane was selected to validate this novel photomicroreactor design. Mass transport limitation was eliminated and indicated by dimensionless numbers Fo and Da II , and photons loss was evaluated considering the absorption and reflection of the microreactor walls. The solvents, photosensitizers, and light sources selections were optimized for achieving better photochemical performance and mechanistic insights. The detailed comparison between the high‐pressure mercury arc lamp and the UV‐LEDs strip revealed great potential of UV‐LEDs as appealing light source for photochemical transformations. Moreover, the reaction mechanism was thoroughly discussed and illustrated by the Jablonski diagram indicating electronic states transitions. According to possible intermediate steps, a kinetic model was proposed with the reaction rate constant being correlated with the photon flux, which is valuable for process optimization and further understanding reaction mechanisms.