Synthesis Of Methyl Phosphonic Dichloride By Gas-solid Phase Catalyzing Method

Using perovskite-type oxides, hexaaluminate and some supported metal catalysts as catalysts, the new technology of synthesis methyl phosphonic dichloride with methane and phosphorus trichloride as reactants through gas-solid phase catalyzing method was studied. The discussion was concentrated on the factors affecting the catalytic properties of catalyst. And the optimal conditions of the catalyst were also identified.The catalytic properties of a variety of perovskite-type oxides for the reaction were studied. The La_0.9K_0.1CoO₃ and La_0.7K_0.3CoO₃ catalysts were screened out. And a further study was done. The main issues such as the factors that affected the catalytic activity of catalyst and the reusing of the catalyst were discussed. The results showed that in the series of perovskite-type of the catalysts with metal of potassium cobalt lanthanum, La_0.9K_0.1CoO₃ and La_0.7K_0.3CoO₃ had a relatively good catalytic activity, and their high temperature resistance and corrosion resistance were also good. The optimal conditions of two catalysts were determined by the discussion of factors affecting catalyst catalytic activities. The optimal conditions of catalyst La_0.9K_0.1CoO₃: the reactants molar ratio CH4:PCl3=5:1, reaction temperature, 300℃, catalyst mesh, (40⁶0 mesh); The optimal conditions of catalyst La_0.7K_0.3CoO₃: the reactants molar ratio CH4:PCl3=5:1, reaction temperature, 300℃, catalyst mesh, (40⁶0 mesh). The effect of the composition of three metals on the catalytic activity of the catalyst was discussed through measuring the catalytic activities of catalysts La1-xKxCoO₃ (x = 0.1, 0.3 and 0.5). The catalytic activities were different with different composition of the three metals in the series of La1-xKxCoO₃. La_0.7K_0.3CoO₃ was the best catalyst, and the catalytic activity of La_0.5K_0.5CoO₃ was the worst.The catalytic performances of hexaaluminate catalyst LaMnAl₁₁O_19-α on the reaction were studied. The effect of calcination temperature on the catalytic activities was investigated, and the results show that the suitable calcination temperature that the catalyst had the best catalytic activity was 1200℃. The optimum conditions of the reaction were obtained by the experiment that investigated the change of the conversion rate varied with the reaction temperature. The optimal conditions were the reactants molar ratio CH4:PCl3=10:1, reaction temperature, 300℃, catalyst mesh, (40⁶0 mesh). The experimental results showed that the LaMnAl₁₁O_19-α had certain catalytic activity and reusability, had a strong high temperature resistance and corrosion resistance.The catalytic performances of catalyst Mo/ZSM-5 on the reaction were studied. The catalyst Mo/ZSM-5 exhibited poor activity in the reaction. The conversion rate was low, and its high temperature resistance and corrosion resistance were also poor. Though the catalyst activity of palladium was the highest in the precious metal catalysts, and Ni catalyst had the best catalyst activity on catalysis and activation of methane in the non-precious metal catalyst, the catalyst activity test result of 1% Pd/AC and 10% Ni/Al₂O₃ shows that both of them exhibited poor activity in the reaction. In general, the catalyst activity of the supported metal catalysts in the reaction was worse than the perovskite-type catalysts, and its high temperature resistance, corrosion resistance and stability were the worst in the three types of catalyst.