Scale‐up strategy for heterogeneous photoelectrocatalytic reactions in flow reactor

Photoelectrocatalysis (PEC) reaction is emerging as a sustainable approach for synthesizing value‐added chemicals. However, the non‐uniform potential/photocurrent density distribution of large‐area photoanode poses significant challenges to its scale‐up, thus hindering its practical applications. Here, we propose and validate a framework for streamlining the scale‐up design of PEC reactions using continuous flow reactor. A universal model based on charge conservation equation is developed to directly extrapolate the photoanode potential/photocurrent density distribution from experimental linear sweep voltammetry measurements, avoiding the need for obtaining highly specific semiconductor and reaction kinetics parameters. The reaction area of reactor is extended by multiplexing photoanodes with optimal size in a scale‐out manner. A barrier‐based method using porous membrane is adopted to achieve uniform flow velocity distribution, overcoming the non‐uniform potential/current distribution caused by insufficient mass transfer. The developed PEC reactor can achieve gram‐scale PEC trifluoromethylation reactions with yields comparable to those in small‐scale batch reactors.