Graphene Oxide-Polyaniline as a Water Dissociation Catalyst in the Interfacial Layer of Bipolar Membrane for Energy-Saving Production of Carboxylic Acids from Carboxylates by Electrodialysis

Bipolar membrane (BPM) was prepared by layer-by-layer casting of the cation-exchange layer (CEL; sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO), interfacial layer (IL), and anion-exchange layer (AEL; quaternized PPO) in the same solvent to achieve good adhesion. Graphene oxide-polyaniline composite (GO-PANI) was introduced in the IL of BPM as water dissociation (WD) catalyst. Under applied reverse bias, water molecules in the IL zone dissociate and generate H+ and OH- useful electrosynthesis by BPM electrodialysis (BPMED). Prepared BPM was assessed by current voltage (i-V) curves and performance of BPMED for converting homologues carboxylates into their corresponding acid and base. Under the operating conditions in BPMED, 71-63% recovery of the different carboxylic acids was recorded with 92-97% CE and 0.90-0.98 kWh kg(-1) energy consumption. Negligible co-ion leakage across the BPM also revealed its efficient nature and product (carboxylic acid) purity. Additionally, low and stable V-diss (0.77-1.12 V) in equilibrium with different carboxylates is responsible for the low energy consumption and making viable high-performance BPM.