Tailoring the Morphology of Nano-γ-MnO 2 Loaded Porous Ti Membrane Electrode for the High Efficiency Oxidation of Cyclohexane Using Double-Cathodic Electrodeposition

Abstract

Potentiostatic electrodeposition with novel double cathodes was employed to fabricate a nano-MnO 2 loading porous tubular Ti membrane electrode ( γ -MnO 2 /Ti) used for the selective oxidation of cyclohexane (CHA) to yield cyclohexanol (A) or cyclohexanone (K) (KA oil). The effect of operating voltage on the electrochemical properties and morphology of the MnO x /Ti electrode was investigated in detail. Results showed that γ - MnO 2 /Ti electrodes with three uniform morphologies such as nanoparticles (NPs), nanowires (NWs) or nanosheets (NSs) were tailored by regulating the electrodeposition voltage from 0.5 to 2.0 V. The γ - MnO 2 NWs/Ti electrode displayed a high electron transfer rate and large effective electrocatalytic specific surface area as well as the best electrochemical performance. Specifically, the γ - MnO 2 NWs/Ti was employed as the anode to constitute an electrocatalytic membrane reactor (ECMR) for KA oil production. Over 99% selectivity for KA oil and 32.4% conversion of CHA were obtained by ECMR. Simultaneously, the γ -MnO 2 NWs/Ti electrode also exhibited superior stability as a result of the high binding energy between γ -MnO 2 NW S catalysts and the Ti substrate, leading to the formation of new Ti–O–Mn bonds. In summary, this work provides a new approach to tailor nanocatalyst-loaded membrane electrodes for heterogeneous electrochemical catalysis.