纳米氧化锡在锌-硝基苯电池反应中的电催化

Electrocatalysis of Nano-Tin Dioxide in the Battery Reaction of Zinc-Nitrobenzene

以氯化锡为原料,四丙基溴化铵为表面活性剂,采用水热法制备纳米二氧化锡(SnO_2)催化剂,并以钛网为基材,制备催化电极.应用扫描电子显微镜(SEM)、X射线衍射分析(XRD)等技术对催化剂进行表征,考察了反应物浓度、反应温度和反应时间对催化剂形貌的影响,并研究了纳米二氧化锡催化剂对锌还原硝基苯原电池反应的电催化性能.结果表明,当氢氧化钠浓度为0.5 mol·L^(-1)、水热反应温度160oC、水热反应时间15 h时,所得SnO_2催化剂是由纳米片构成的刺球状颗粒,且粒径最小,约17 nm.与平板铂电极相比,制备的催化电极对硝基苯电还原具有更高的催化活性,硝基苯转化率为74%,最大放电功率为21.9 mW·cm^(-2),远高于平板铂电极.硝基苯的主要还原产物为苯胺、对乙氧基苯胺和对氯苯胺.

The tin dioxide （SnO2） nanoparticles were synthesized by using a simple hydrothermal route in the presence of tetrapropyl ammonium bromide （TPAB） as a surfactant. Accordingly, the titanium mesh based SnO2 catalyst electrode was prepared. The morphologies and structures of SnO2 nanostructures were characterized by scanning electron microscopy and X-ray diffraction spectrometry. The influences of reactant concentration, reaction temperature and time on the morphology of the products were in- vestigated in detail. The electrocatalytic performance of SnO2 for the reduction of nitrobenzene with zinc was studied. Possible formation process and growth mechanism for such hierarchical SnO2 nanostructures have been proposed based on the experimental resuits. The results showed that when the concentration of NaOH was 0.5 mol. L-1, the hydrothermal reaction temperature was 160℃, hydrothermal reaction time was 9 h, the as-prepared SnO2 catalyst appeared thorny spheric particles consisting of nanosheets with the particle size as small as 17 urn. Compared with Pt electrode, the catalyst electrode exhibited higher catalytic activity toward the electrochemical reduction of nitrobenzene. The conversion rate of nitrobenzene was up to 74% and the maximum discharge power density was 21.9 mW. cm-2, which are much better than those with platinum electrode. The main reduction products of nitrobenzene were aniline, p-phenetidine and p-chloroaniline.