Enhanced n-propanol oxidation coupled with hydrogen evolution by electrocatalytic membrane structured reactor via flow-through operation

An electrocatalytic membrane structured reactor (EMSR) fabricated by loading MnO2 catalyst in Ti membrane pores for oxidation of n-propanol coupled with hydrogen evolution. During the process of n-propanol oxidation coupled with hydrogen evolution by MnO2@Ti EMSR via flow-through mode, the conversion rate of n-propanol was increased by 44%, the selectivity of propionic acid was increased by 33%, and the Faraday efficiency was increased by 59%, compared with those of MnO2/Ti membrane with MnO2 immobilized on the membrane surface. Enhanced contact and mass transfer are two contributors for the catalytic performance improvement by MnO2@Ti EMSR via flow-through mode. Besides, the cell voltage during n-propanol oxidation coupled with hydrogen production is decreased by 305 mV with energy consumption reduced by 0.73 kWh NmH2 -3 , compared with those of hydrogen evolution by water splitting with oxygen evolution reaction. The achievements of this work provide a promising strategy for coproduction of propionic acid and hydrogen.

Automated summary

An electrocatalytic membrane structured reactor (EMSR) with MnO2 catalyst loaded in Ti membrane pores was used for n-propanol oxidation coupled with hydrogen evolution. MnO2@Ti EMSR via flow-through mode significantly enhanced the conversion rate of n-propanol, selectivity of propionic acid, and Faraday efficiency compared to MnO2/Ti membrane with immobilized MnO2. The improved catalytic performance was attributed to enhanced contact and mass transfer. In addition, the cell voltage and energy consumption during n-propanol oxidation coupled with hydrogen evolution were reduced compared to water splitting with oxygen evolution reaction. These findings provide a promising strategy for coproduction of propionic acid and hydrogen.