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用MSCV法研究了活性炭及乙炔黑在pH1—12范围内的电氧化,两种炭的φ_s、η_s与pH的关系(φ_(?)及η_(?)是CO_2开始析出的电位及超电位)以及I_M、φ_I与pH的关系(I_M、φ_I分别为给定电位下的质谱强度及给定I_M下的电位)均为一折点在的pH～7的折线.这暗示酸、碱介质中有不同的氧化机理.pH>7时,η_s及Tafel斜率b均较pH<7时的大.似可推断在酸性介质中形成CO_2所需的氧原子来自水分子放电,其活性明显大于来自碱性溶液中OH~-放电产生的氧原子.因而在酸性介质中炭氧化为CO_2较碱性介质中易于进行.两种炭之间氧化活性亦有明显区别.活性炭的φ_(?)比φ°(O_2/H_2O)负400—600mV;乙炔黑的φ_s则接近或正于φ°(O_2/H_2O).前者的I_M及b均较后者大.乙炔黑较低的氧化活性可归因于其较高的有序性结构.
The electrochemical oxidation of activated carbon and acetylene black in the pH range of 1 to 12 was studied by MSCV method. The relationship between φ_s, η_s and pH of the two carbons (φ_ (?) And η_ (?) Is the potential and overpotential for the onset of CO_2) And the relationship between I_M, φ_I and pH (I_M, φ_I are the mass spectra at a given potential and the potentials at a given I_M, respectively) are broken lines at a break at pH ~ 7. This implies that there is Different oxidation mechanism.pH> 7, η_s and Tafel slope b than pH <7. It seems that the oxygen atoms required for the formation of CO 2 in acidic medium from water molecules discharge, the activity was significantly greater than that from alkaline The oxygen atoms generated by the OH ~ - discharge in the solution are easy to be oxidized to CO_2 in acidic medium than the alkaline medium.The oxidation activity of the two kinds of carbon is also obviously different.The ratio of φ_ (? O_2 / H_2O) negative 400-600mV acetylene black φ_s close to or positive φ ° (O_2 / H_2O) .The former I_M and b are greater than the latter acetylene black lower oxidation activity can be attributed to its more High order structure.