Investigation of electrocatalytic activity of nanostructure Ce-doped MnOx sol–gel coating deposited on porous Ti membrane electrode

Ce-doped MnO x /Ti electrocatalytic membrane electrodes were prepared by doping rare earth element Ce into manganese oxide (MnO x ) via sol–gel method, and coated on the porous Ti substrate membrane electrode. In order to evaluate electrocatalytic activity of the Ce–MnO x /Ti electrode, a functional electrocatalytic membrane reactor (ECMR), which assembled a Ce–MnO x /Ti electrode as an anode and a stainless steel mesh as a cathode, has been employed for phenolic wastewater treatment. The results revealed that a new crystal form Ce 2 O 3 appeared after doping Ce into the system, and the urchinlike morphology and smaller grain size of Ce–MnO x led the catalytic activity of the composite membrane electrode to improve. Moreover, the 25 mol% Ce–MnO x /Ti (C25MT) composite membrane electrode represented the best activity in the degradation of phenolic wastewater. During ECMR with C25MT operation under the conditions of 450 mg/L phenolic wastewater (500 mL), residence time of 5 min, pH of 1–13 and current density of 0.3–1.2 mA/cm 2 , the highest degradation efficiency of phenolic wastewater achieved in current density of 0.9 mA/cm 2 and pH of 7, that is, the achieved remove rate of phenol, COD and TOC were 99.61, 93.12, and 84.23%, respectively. Finally, the effective reusability of C25MT composite membrane electrode was assessed, and a proposed reaction mechanism has been analyzed in the ECMR operation.