五氧化二钒催化钾碱液吸收二氧化碳的机理

CATALYTIC ACTIVITY OF VANADIUM PENTOXIDE FOR THE ABSORPTION OF CARBON DIOXIDE BY POTASSIUM CARBONATE SOLUTION

从五氧化二钒(V_2O_5)的物理化学性质出发,研究了V_2O_5加快CO_2在钾碱液(K_2CO_3)中的吸收速率的化学作用机理。实验证明:当9<pH<12时,V_2O_5在钾碱液中以V_2O_7^(4-)和V_4O_(12)^(4-)两种形态存在,其中V_2O_7^(4-)能与CO_2相互作用,形成不稳定的中间体,从而加速CO_2在气-液相间的传递。化学吸收的增强因子与V_2O_7^(4-)的浓度及溶液的pH值有关,最佳的pH范围是10.6到10.8,V_2O_5的加入量应保证溶液的pH值处于最佳范围为宜。

The chemical mechanism that vanadium pentoxide, as an additive, enhances the absorption rate of carbon dioxide in aqueous potassium carbonate solution has beensuggested Experiments proved that V_2O_5 exists as V_2O_7^(4-) and V_4O_(12)^(4-) in the carbonate solu-tion, as pH value is in the range of 9--12. The catalytic action of V_2O_5 is only re-lated to the concentration of V_2O_7^(4-) and pH value of the solution, the optimum rangeof pH value is 10.6 to 10.8, and the quantity of V_2O_5 added has to be restricted inorder to maintain the optimized pH range.