TiO_2光催化降解H_2S的利用率研究

Variation of TiO_2 utilization ratio in H_2S photocatalytic degradation

采用孔径48μm不锈钢网负载TiO2薄膜作为光催化材料,以低功率紫外灯作为光源,在连续性反应器内降解H2S。首先探讨了气体含氧量对H2S光催化氧化产物和TiO2利用率的影响,之后分析了H2S体积分数、光照面积以及TiO2用量等因素对TiO2利用率和失活速率的影响。结果表明,当反应气中氧含量从0升高至1.0%时,H2S的主要氧化产物由单质硫变成SO2或SO2-4,催化剂利用率先升高后降低,氧和H2S的投入量之比n(O2)∶n(H2S)约为50∶1时TiO2的利用率最高;降低H2S的初始体积分数或增大TiO2的负载面积均可减缓催化剂失活,提高TiO2利用率;不锈钢网面积为168cm2时,催化剂的最佳负载量为0.35g左右。

H2S was degraded in a continuous photocatalytic reactor,using low-powered UV-light as an optical source,and a TiO2 film loaded on a stainless steel network as a photocatalyst.The influence of O2 concentration on photocatalytic oxidation products of H2S was first studied.The results showed that H2S is oxidized to sulfur in the absence of O2,but when the content of O2 was increased to 1%,SO2 and SO2-4 were the major products.The photocatalytic activity of the TiO2 film is reduced by both S and SO2-4 deposition,leading to the incomplete removal of H2S.Further studies of the inactivation rate and utilization ratio of the TiO2 film were carried out.The optimum proportion of H2S to O2 was found to be about 1∶ 50 under the experimental conditions,and the TiO2 utilization ratio can be increased by decreasing the H2S content or increasing the irradiation area.When the stainless steel network area was 168cm2,the optimum dosage of the TiO2 film was about 0.35g.