The effect of pyridine on the parameters of electrolysis in acidic and neutral solutions of zinc sulfate was studied in a wide range of potentials and current densities. The effect of pyridine additives on the parameters of cationic discharge from the zinc sulfate electrolytes, including sulfuric acid, was analyzed. The zinc-to-sulfuric acid mass ratio in one of the three electrolytes corresponded to the composition of the commercial solutions utilized for zinc electrolysis. It was shown that an increase in the electrolyte acid content and cathode potential results in higher cation discharge rate, while an addition of pyridine causes it to decrease. The obtained experimental data evidence the preferential effect of pyridine on hydrogen cation discharge in zinc-containing electrolyte solution. It was noted that an increase in overvoltage accelerates quicker in the solution containing pyridine additives at a current density ( j ) in excess of 300 A/m 2 , while without such additives it actually slows down. This is associated with the ability of pyridine additive to protonate and absorb a significant amount of hydrogen causing a stronger inhibition of hydrogen discharge compared to zinc in the areas with high current density. It was shown that within certain regions of the voltammetric curves with the current density exceeding 300 A/m 2 , the exchange current (i ex ) increases by about nine times at elevated cathode potentials and increased pyridine concentrations to 0.3 mg/liter. However, when the pyridine concentration increases to 0.6 mg/liter, the exchange current, same as the rate of ionic discharge, decreases, which is consistent with the Butler-Volmer equation for a cathodic process at high overvoltage values associated with increased current densities. The calculations of the transfer coefficients made it possible to conclude that at current densities of 600 A/m 2 and higher, the transfer coefficient approaches zero, and the process of cationic discharge from acidic electrolytes with the addition of pyridine proceeds in an activationless mode. The results of the conducted study have led to the following important conclusion in terms of practical use of zinc electrolysis: in order to exclude the negative effect of pyridine, the process should be conducted below the current densities of 300–350 A/m 2 .

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不同电流密度下吡啶对锌电解参数的影响

在很宽的电位和电流密度范围内研究了吡啶对硫酸锌酸性和中性溶液中电解参数的影响。分析了吡啶添加剂对硫酸锌电解质（包括硫酸）的阳离子放电参数的影响。三种电解质之一中锌与硫酸的质量比对应于用于锌电解的商业溶液的组成。结果表明，电解质酸含量和阴极电位的增加导致更高的阳离子放电率，而吡啶的添加导致其降低。获得的实验数据证明了吡啶对含锌电解液中氢阳离子放电的优先影响。注意到在电流密度 (j) 超过 300 A/m 2 时，在含有吡啶添加剂的溶液中，过电压的增加加速得更快，而没有这种添加剂，它实际上会减慢。这与吡啶添加剂质子化和吸收大量氢气的能力有关，与高电流密度区域中的锌相比，导致更强的氢气放电抑制。结果表明，在电流密度超过 300 A/m 2 的伏安曲线的某些区域内，交换电流 (i ex ) 在阴极电位升高和吡啶浓度增加到 0.3 mg/l 时增加了大约九倍。然而，当吡啶浓度增加到 0.6 mg/L 时，交换电流与离子放电速率相同，这与在与电流密度增加相关的高过电压值下的阴极过程的 Butler-Volmer 方程一致。转移系数的计算使得可以得出结论，在 600 A/m 2 或更高的电流密度下，转移系数接近于零，并且添加吡啶的酸性电解质的阳离子放电过程以非活化模式进行。所进行的研究结果在锌电解的实际应用方面得出了以下重要结论：为了排除吡啶的负面影响，该过程应在低于 300-350 A/m 2 的电流密度下进行。转移系数的计算使得可以得出结论，在 600 A/m 2 或更高的电流密度下，转移系数接近于零，并且添加吡啶的酸性电解质的阳离子放电过程以非活化模式进行。所进行的研究结果在锌电解的实际应用方面得出了以下重要结论：为了排除吡啶的负面影响，该过程应在低于 300-350 A/m 2 的电流密度下进行。转移系数的计算使得可以得出结论，在 600 A/m 2 或更高的电流密度下，转移系数接近于零，并且添加吡啶的酸性电解质的阳离子放电过程以非活化模式进行。所进行的研究结果在锌电解的实际应用方面得出了以下重要结论：为了排除吡啶的负面影响，该过程应在低于 300-350 A/m 2 的电流密度下进行。