电化学合成乙醇铪的参数优化、表征和热性能分析

摘要

采用电化学方法合成乙醇铪,优化电化学合成过程中的各个参数,包括四乙基溴化铵浓度(c):0.01~0.06 mol/L、溶液温度(t):30~78°C、极距(D):2.0~4.0 cm和电流密度(J):100~400 A/m2.在最优条件(c=0.04 mol/L、t=78°C、D=2.0 cm,J=100 A/m2)下获得的电化学产物通过减压蒸馏(5 kPa)进一步分离提纯.对所得最终产物通过红外光谱和核磁共振进行表征.结果表明,产物为乙醇铪.最终产物杂质含量通过ICP分析,结果表明,乙醇铪在最终产物的含量超过99.997%.采用TG/DTG对所得产物乙醇铪进行热分析,得到其蒸发热焓为79.1 kJ/mol,表明所得乙醇铪适合原子沉积法制备氧化铪.%Hafnium ethoxide was synthesized using electrochemical method. Optimization experiments were used to optimize various parameters namely Et4NBr concentration(c): 0.01?0.06 mol/L, solution temperature (t): 30?78 °C, polar distance (D): 2.0?4.0 cm and current density (J): 100?400 A/m2. The electrolytic products obtained under optimum conditions ofc=0.04 mol/L, t=78 °C,D=2.0 cm andJ=100 A/m2 were further isolated by vacuum distillation under 5 kPa. The product was characterized by Fourier transform infrared (FT-IR) spectra, nuclear magnetic resonance (NMR) spectra. The results indicated that the product was hafnium ethoxide. ICP analysis suggested that the content of hafnium ethoxide in the final product exceeded 99.997%. Thermal properties of the product were analyzed by TG/DTG. The vaporization enthalpy of hafnium ethoxide was found to be 79.1 kJ/mol. The result confirmed that hafnium ethoxide was suitable for the preparation of hafnium oxide by atomic layer deposition.