NanoTiO2-CNT复合膜电极在DMF溶液中对糠醛的异相电催化还原

通过在乙醇中电化学溶解Ti金属阳极合成前驱体Ti(OEt)4和溶胶-凝胶法在Ti表面修饰一层纳米TiO2-碳纳米管(nanoTiO2-CNT)复合膜, 采用循环伏安和电解合成法研究了nanoTiO2-CNT复合膜电极在N, N-二甲基甲酰胺(DMF)中的氧化还原行为以及对糠醛(furfural)还原的电催化活性. 结果发现, nanoTiO2-CNT电极在阴极扫描时有两对氧化还原峰, 可逆半波电位E r1/2 分别为－1.27 V和－2.44 V(vs SCE, 扫描速度100 mV•s-1), 分别对应于TiO2/Ti2O3氧化还原电对的可逆电极过程和TiO2/Ti(OH)3电对的准可逆电极过程；在DMF电解液中nanoTiO2-CNT复合膜中的Ti(IV)/Ti(III)氧化还原电对作为媒质间接电还原糠醛为糠醇, 反应机理为电化学偶联随后化学催化反应(EC′)机理.

Heterogeneous Electrocatalytic Reduction of Furfural on Nanocrystalline TiO2-CNT Complex Film Electrode in DMF Solution

The precursor Ti(OEt)4 was prepared by anodic dissolution of metallic titanium in absolute ethanol and directly hydrolyzed to prepare nanocrystalline TiO2-carbon nanotube(nanoTiO2-CNT) complex film by a sol-gel process. Redox behavior and electrocatalytic activities of the nanoTiO2-CNT complex film electrode were investigated by cyclic voltammetry (CV) and bulk electrolysis in DMF solution. It was found that there were two pairs of well-defined redox peaks for nanoTiO2-CNT complex film electrode with Er1/2 of －1.27 V and －2.44 V(vs SCE) at 100 mV•s-1 in correspondence with TiO2/Ti2O3 reversible and TiO2/Ti(OH)3 quasi-reversible electrode process, and the heterogeneous electrocatalytic reduction activities of TiO2/Ti(OH)3 redox system for furfural; The indirect electroreduction of furfural to furfural alcohol by Ti(IV)/Ti(III) redox system on nanoTiO2-CNT complex film surface in DMF. The electrode reaction mechanism is the called catalytic (EC′) mechanism.