Ti改性Mn基催化剂常温去除臭氧的性能研究与改进

Research and improvement on the performance of Ti modified Mn based catalysts for removing ozone at room temperature

采用原位在Al网上生长γ-Al_(2)O_(3)层,制备MnTi_(2.2)/γ-Al_(2)O_(3)/Al结构化催化剂以提高MnO_(x)催化剂的分散性及在高湿度环境下常温去除O_(3)的催化活性。基于MnTi_(2.2)/γ-Al_(2)O_(3)/Al催化剂的反应性能,通过高湿高浓度O_(3)加速失活实验探究催化剂的失活原因,并筛选出抗湿性能优良的MnTi_(2.2)/γ-Al_(2)O_(3)/Al结构化催化剂。结果表明,Ti掺杂的MnTi_(2.2)/γ-Al_(2)O_(3)/Al催化剂在RH=50%下有近100%的降解转化率,RH=70%下有近95%的催化降解O 3的性能,RH=90%时,仍可保持54%的催化性能。通过3000 h的加速失活测试结果发现,水分子对MnTi_(2.2)/γ-Al_(2)O_(3)/Al催化剂活性位点的竞争吸附是催化剂失活的主要原因,对MnTi_(2.2)/γ-Al_(2)O_(3)/Al催化剂进行外部疏水化处理可有效减少水分子对催化剂活性位点的侵占,提升催化剂在高湿度条件下的催化降解性能。

This study used in-situ growth ofγ-Al_(2)O_(3)layer on Al mesh and prepared structured MnTi_(2.2)/γ-Al_(2)O_(3)/Al catalyst to improve the dispersion of MnO _(x) catalyst and its catalytic activity for removing O_(3) at room temperature in high humidity environment.Based on the reaction performance of the MnTi_(2.2)/γ-Al_(2)O_(3)/Alcatalyst,the deactivation reasons of the catalyst were investigated through high humidity and high concentration O_(3) accelerated deactivation experiments,and structured MnTi_(2.2)/γ-Al_(2)O_(3)/Al catalysts with excellent moisture resistance were selected.The results showed that the MnTi_(2.2)/γ-Al_(2)O_(3)/Al catalyst doped with Ti had a degradation conversion rate of nearly 100%at RH=50%,and a catalytic degradation performance of nearly 95%for O 3 at RH=70%.When RH=90%,the catalytic performance could still be maintained at 54%.Through an accelerated deactivation test of 3000 hours,it was found that the competitive adsorption of water molecules on the active sites of the MnTi_(2.2)/γ-Al_(2)O_(3)/Al catalyst was the main reason for catalyst deactivation.External hydrophobic treatment of the MnTi_(2.2)/γ-Al_(2)O_(3)/Al catalyst could effectively reduce the invasion of water molecules on the active sites of the catalyst,further enhancing the catalytic degradation performance of the catalyst under high humidity conditions.