纳米晶氧化铜的制备及其催化苯酚氧化性能

采用沉淀法制备了纳米晶氧化铜催化剂,通过XRD、TEM及N2吸附-脱附法对纳米晶氧化铜催化剂的微观结构进行了表征。表征结果显示,制备的纳米晶氧化铜的平均粒径为8.5 nm,比表面积为56.2 m2/g。研究了纳米晶氧化铜催化氧化苯酚的性能,同时对反应条件进行了优化。实验结果表明,自制的纳米晶氧化铜催化剂具有优良的催化性能,反应条件(如催化剂用量、抗坏血酸用量、溶剂中醋酸含量及反应温度)对苯二酚收率有显著影响。在苯酚浓度1.28 mol/L、催化剂用量0.572mol/L、抗坏血酸用量0.796 mol/L、20%(φ)醋酸水溶液(50 mL)为溶剂、氧气流量70~80 mL/min、反应温度308 K的优化条件下反应90 min,苯二酚收率达14.90%。

Preparation of Copper Oxide Nanocrystal and Its Catalysis Performance in Phenol Oxidation

Copper oxide nanocrystals were synthesized through a precipitation method and were characterized by means of XRD,TEM and N2 adsorption-desorption.The results showed that the average crystallite size of the copper oxide nanocrystals was 8.5 nm and the specific surface area was 56.2 m2/g.The catalytic performance of the copper oxide nanocrystals in oxidation of phenol with oxygen to dihydroxybenzene was studied and the reaction conditions were optimized.It was found that the effects of catalyst concentration,ascorbic acid concentration,acetic acid volume fraction and reaction temperature on the didydroxybenzene(DHB) yield were significant.The DHB yield could reach 14.90% under the optimal conditions:phenol concentration 1.28 mol/L,copper oxide catalyst concentration 0.572 mol/L,ascorbic acid concentration 0.796 mol/L,20%(φ) acetic acid solution 50 mL,oxygen flux 70-80 mL/min,reaction temperature 308 K and reaction time 90 min.