Direct methane conversion under mild conditions is one of the most attractive targets in catalysis, and photocatalysis offers a route at ambient temperature. A workable experiment has to solve three coupled problems: getting methane to the catalyst (mass transfer), exciting the chemistry (light), and proving what happened (quantification). A microdroplet reactor addresses the first and supports the other two.
Configure the gas-liquid dispersion first: methane pressure or flow, liquid composition and the droplet generation mode. Verify the dispersion visually or optically, because coalesced units quietly erase the enhancement. Confirm the system is leak-tight, methane leaks are a safety issue as well as a data issue.
Select the light source from the catalyst's absorption: UV-rich systems for wide-gap photocatalysts, visible configurations for sensitized or plasmonic ones. Calibrate intensity at the dispersion volume, not the vessel wall, and control temperature actively, because the droplet field can otherwise act as a distributed absorber and heat the liquid.
Both gas-phase products (CO, CO2, ethane) and liquid-phase products (methanol, formate) can form. Define the analytical chain in advance: gas products by online detection or GC, liquid products by ion chromatography, NMR or colorimetric assays after defined irradiation times. Include blank runs without catalyst and dark controls, they define the floor of your evidence.
Fix methane/liquid ratio, droplet field stability, light intensity, temperature and sampling time. Vary one at a time. Methane conversion rates reported without these conditions cannot be reproduced by anyone, including the original lab.
Perfectlight's PLR-CTPR system packages the dispersion, irradiation and sampling stages; see reaction systems and online gas analysis.
