Paired Electro-Generation of Glyoxylic Acid Using Bipolar Membrane Made from Sodium Alginate and Chitosan

摘要

Sodium alginate (SA) and chitosan (CS) were modified with Ca~(2+) and glutaralde-hyde linking reagents to prepare the mSA/mCS bipolar membrane (BPM). The morphology of the membrane was characterized by SEM. The membrane was used as a separator in an electrolysis cell for the production of glyoxylic acid simultaneously at both the cathode and the anode. The catholyte consisted of a mixture of saturated oxalic acid and 0.1 mol/L HCl, and the anolyte was a mixture of gly-oxal (10wt.%) and KBr (10 wt.%). A nickel mesh was placed on the surface of the mSA cation exchange layer to act as the cathode, and the anode was PbO2. The electrolysis voltage was as low as 2.7 V during operation at room temperature with a current density of 20mA · cm~(-2). Current efficiencies reached 82.9% in the cathode chamber and 75.7% in the anode chamber.