掺杂离子对Fenton试剂氧化降解瓦斯效应的影响

Fenton试剂降解瓦斯是利用Fe2+催化H2O2产生羟基自由基（·OH）氧化甲烷而实现的，为抑制Fenton试剂中H2O2无效分解，进一步提高Fenton试剂氧化降解瓦斯效应，通过掺杂硬酸离子保持Fenton试剂的稳定性，系统考察了Mg2+对Fenton试剂稳定性、羟基自由基表观生成率、瓦斯降解率的影响规律。实验结果表明：Mg2+可有效保持Fenton试剂的稳定性，提高Fenton试剂产生羟基自由基和降解瓦斯的能力；当c(Mg2+)为0.5 mmol/L时，反应0.5 h后羟基自由基表观生成率最高可达80.41%，瓦斯降解效率可从传统Fenton试剂的25%提高到40%。应用量子化学理论验证了掺杂硬酸离子是通过降低过氧化羟基自由基（HOO·）的活度来延长Fenton链式反应中链的传递过程，减少H2O2无效分解，提高Fenton试剂的稳定性、羟基自由基表观生成率和降解瓦斯效应，为Fenton试剂高效氧化降解瓦斯提供理论依据。

Effects of doping ions on the degradation of coal-mine gas via Fenton reagent

The degradation of coal-mine gas with Fenton reagent is carried out through the oxidation reactions between methane and hydroxyl radicals (·OH) generated via the catalytic decomposition of H2O2 with Fe2+.In order to restrain the invalid decomposition and improve the efficiency of coal-mine gas degradation with Fenton reagent,the stability of Fenton reagents can be kept by doping hard-acid ions,such as Mg2+,Ca2+,and Na+,etc.The influence rules of Mg2+ on the stability of Fenton reagents,the apparent formation rate of ·OH and the degradation ratio of methane were systematically investigated.The experimental results demonstrate that the introduction of Mg2+ can effectively maintain the stability of Fenton reagents and improve the efficiency of gas degradation and ·OH formation via Fenton reagents.When 0.5 mmol/L of Mg2+ is added,the apparent formation rate of ·OH reaches to a maximum of 80.41% after 0.5 h.Meantime,the degradation percentage of coal-mine gas increases up to 40%,which is much higher than that obtained in the traditional Fenton system.Furthermore,by means of quantum chemistry theory,it is evidenced that the transmission process of chain reactions with Fenton reagents can be lengthened by decreasing the activity of peroxy-radicals (HOO·) via doping hard-acid ions.The special effect of hard-acid ions can decrease the ineffective decomposition of H2O2,promote the stability of Fenton reagents,and enhance the efficiency of apparent formation rate of ·OH and degradation ratio of gas,which present the theoretical basis for the efficient degradation of coal-mine gas.