Preparation Of One-dimensional CoO_x Nanostructure In Situ Supported Electrocatalytic Membrane And Its Catalytic Oxidation Performance

Development of benzoic acid synthesis system of green,high efficiency,high selectivity is the key research direction of the fine chemicals.The preparation of benzoic acid exited severe corrosion,pollution,product separation hardly,complex operation and so on for the chemical industry.We have developed a new electrocatalytic membrane electrode by a one dimensional CoOx nanostructure in-situ loading on Ti membrane by hydrothermal method.The obtained membrane electrode of CoOx nanowires was in-situ loaded on the Ti membrane and employed as an anode with a stainless steel as a cathode to construct the electrocatalytic membrane reactor(ECMR)for benzyl alcohol(BA)oxidation to product benzoic acid.The controllable oxidation of BA could be achieved by controlling the main conditions,such as the BA concentration,residence time,and current density.This electrocatalyst exhibits a 99%conversion and 92%selective of benzyl alcohol to benzoic acid under the conditions of BA concentration 10 mmol L-1 residence time 14 min,current density 2.6 mA cm-2,temperature 21 ? in the reaction solution.Mechanism research showed that ECMR emploied to produce benzoic acid from BA is by hydroxyl radical as initiator,mainly induced Co?=O oxidation to Co?=O for benzyl alcohol oxidation.At the same time,due to the unique structure of one-dimensional CoOx nanowires,which can be exposed more active site so as to further promote benzaldehyde.In addition,comparative electrocatalytic properties of membrane electrode with different morphologies,we prepared one-dimensional CoOx nanowires,one-dimensional CoOx nanoneedles and zero-dimensional CoOx nanoparticles loading on Ti membrane to build ECMR for wastewater treatment.The reaction condition is that Na2SO4 as electrolyte,concentration of 14.4 g L-1,phenol concentration of 470 mg L-1 the current density of 1.0 MA cm-2,pH value of 7.0,residence time of 14 min.Results showed that nanoneedle CoOx membrane electrode showed best degradation of phenol,the removal rate of COD and TOC is 88.6%and 73.8%under atmospheric pressure,respectively.