Redox behavior and electrocatalytic activities of the Ti/nano\|TiO\-2 electrode were investigated by cyclic voltammetry(CV) and bulk electrolysis. The results indicate that there are two pairs of well\|defined redox p...Redox behavior and electrocatalytic activities of the Ti/nano\|TiO\-2 electrode were investigated by cyclic voltammetry(CV) and bulk electrolysis. The results indicate that there are two pairs of well\|defined redox peaks for Ti/nano\|TiO\-2 film electrode in the 1 mol/L H\-2SO\-4 and 1 mol/L NaOH at 0.1 V/s corresponding to TiO\-2/ Ti\-2O\-3 and TiO\-2/Ti(OH)\-3 reversible electrode process. In 1 mol/L NaOH medium the peak potential evidently shift to the negative value with \%E\%\+r\-\{1/2\} being -1.38 and -1.72 V(\%vs\%.SCE), and the heterogeneous electrocatalytic reduction activities of TiO\-2/Ti\-2O\-3 redox for \%p\%\|nitrobenzoic acid (PNA) is very high. The indirect electroreduction of PNA to \%p\%\|aminobenzoic acid (PAA) by Ti\+Ⅳ/Ti\+Ⅲ redox system on nanocrystalline TiO\-2 film surface was found, and the electrode reaction mechanism is called electro\|catalytic(EC) mechanism. In the preparative electrolysis, the current efficiency was over 90%.展开更多
Poly p-aminobenzoic acid has been synthesized by chemical oxidation method. The inhibitive effect of poly p-aminobenzoic acid on iron in 1 mol/L HCI solution was investigated by polarization and electrochemical impeda...Poly p-aminobenzoic acid has been synthesized by chemical oxidation method. The inhibitive effect of poly p-aminobenzoic acid on iron in 1 mol/L HCI solution was investigated by polarization and electrochemical impedance spectroscopy and compared with that of monomer p-aminobenzoic acid. The effectiveness of poly p-aminobenzoic acid is very high in comparison with that of monomer. The results show that both cathodic and anodic processes were suppressed by p-aminobenzoic acid and poly p-aminobenzoic acid of iron dissolution in 1 mol/L HCI by their adsorption on the iron surface. The inhibition efficiency of both p-aminobenzoic acid and poly p-aminobenzoic acid were found to increase with the inhibitor concentrations. Ultraviolet （UV） reflectance studies of the iron surface after exposure to inhibitor acid show that poly p-aminobenzoic acid is strongly adsorbed on iron surface.展开更多
以产率为指标,对氨基苯甲酸和无水乙醇为原料,浓硫酸为催化剂,通过L 9(34)的正交试验优化超声加热法合成苯佐卡因的工艺条件,优化后的工艺条件是:B 3C 3D 2 A 1,即催化剂与对氨基苯甲酸比例为1:4.8、超声时间为60 min、超声温度为78℃...以产率为指标,对氨基苯甲酸和无水乙醇为原料,浓硫酸为催化剂,通过L 9(34)的正交试验优化超声加热法合成苯佐卡因的工艺条件,优化后的工艺条件是:B 3C 3D 2 A 1,即催化剂与对氨基苯甲酸比例为1:4.8、超声时间为60 min、超声温度为78℃、酸醇比为1:5(w/V),产率达80.60%。该方法具有产率较高、操作方便、时间短、节能减耗等优点,为苯佐卡因合成的实验教学和生产工艺设计开发提供一种较好的方法。展开更多
文摘Redox behavior and electrocatalytic activities of the Ti/nano\|TiO\-2 electrode were investigated by cyclic voltammetry(CV) and bulk electrolysis. The results indicate that there are two pairs of well\|defined redox peaks for Ti/nano\|TiO\-2 film electrode in the 1 mol/L H\-2SO\-4 and 1 mol/L NaOH at 0.1 V/s corresponding to TiO\-2/ Ti\-2O\-3 and TiO\-2/Ti(OH)\-3 reversible electrode process. In 1 mol/L NaOH medium the peak potential evidently shift to the negative value with \%E\%\+r\-\{1/2\} being -1.38 and -1.72 V(\%vs\%.SCE), and the heterogeneous electrocatalytic reduction activities of TiO\-2/Ti\-2O\-3 redox for \%p\%\|nitrobenzoic acid (PNA) is very high. The indirect electroreduction of PNA to \%p\%\|aminobenzoic acid (PAA) by Ti\+Ⅳ/Ti\+Ⅲ redox system on nanocrystalline TiO\-2 film surface was found, and the electrode reaction mechanism is called electro\|catalytic(EC) mechanism. In the preparative electrolysis, the current efficiency was over 90%.
文摘Poly p-aminobenzoic acid has been synthesized by chemical oxidation method. The inhibitive effect of poly p-aminobenzoic acid on iron in 1 mol/L HCI solution was investigated by polarization and electrochemical impedance spectroscopy and compared with that of monomer p-aminobenzoic acid. The effectiveness of poly p-aminobenzoic acid is very high in comparison with that of monomer. The results show that both cathodic and anodic processes were suppressed by p-aminobenzoic acid and poly p-aminobenzoic acid of iron dissolution in 1 mol/L HCI by their adsorption on the iron surface. The inhibition efficiency of both p-aminobenzoic acid and poly p-aminobenzoic acid were found to increase with the inhibitor concentrations. Ultraviolet （UV） reflectance studies of the iron surface after exposure to inhibitor acid show that poly p-aminobenzoic acid is strongly adsorbed on iron surface.
文摘以产率为指标,对氨基苯甲酸和无水乙醇为原料,浓硫酸为催化剂,通过L 9(34)的正交试验优化超声加热法合成苯佐卡因的工艺条件,优化后的工艺条件是:B 3C 3D 2 A 1,即催化剂与对氨基苯甲酸比例为1:4.8、超声时间为60 min、超声温度为78℃、酸醇比为1:5(w/V),产率达80.60%。该方法具有产率较高、操作方便、时间短、节能减耗等优点,为苯佐卡因合成的实验教学和生产工艺设计开发提供一种较好的方法。
