Preparation Of The SrM_xZr_（1-x）O_3-δ Perovskite Catalysts And Its Catalytic Properties And Mechanism In Catalytic Ozonation

Catalytic wet ozone oxidation（CWOO）is one of the most efficient waste water treatment technologies.Its core lies in the development of efficient and highly stable catalysts.A large number of studies have demonstrated that doped perovskite catalysts exhibit excellent catalytic effects in CWOO.In this paper,SrM_xZr_（1-x）O_3-δtype perovskite catalysts were prepared and used in CWOO,and the CWOO of m-cresol was taken as the probe reaction.Various novel perovskite catalysts development methods（artificial intelligence and catalyst reduction techniques）were introduced,combined with various characterization tools,in order to develop highly efficient and highly stable perovskite catalysts for CWOO and to study its reaction mechanism.Firstly,SrZrO₃ catalysts doped with Fe,Co and Mn were synthesized by the coprecipitation method respectively.These catalysts were used in the CWOO oxidation.It was found that the doping of Fe could significantly enhance the catalytic activity of SrZrO₃ catalyst.SrFe_0.1Zr_0.9O_3-δis superior to the other two catalysts.By combining artificial intelligence simulation optimization and experiments,the doping amount of Fe was optimized and the optimal performance catalyst was prepared:SrFe_0.13Zr_0.87O_3-δ.The experimental results show that the TOC removal rate is increased by 2times in the CWOO reaction system with SrFe_0.13Zr_0.87O_3-δcompared with the ozone reaction alone,which proves the excellent activity of iron-doped perovskite catalysts.The experimental results showed that the TOC removal rate reached2 times of that without the catalyst,which proved the excellent activity of the perovskite catalysts.Next,the resulting SrFe_0.13Zr_0.87O_3-δcatalyst was subjected to reduction treatment to obtain the reduced state H-SrFe_0.13Zr_0.87O_3-δcatalyst,and the catalytic performance before and after reduction was compared.It was found that after the reduction treatment,the TOC removal rate increased by 60%compared with that before reduction,and the catalyst performance was greatly improved.The catalytic mechanism of the reduced state H-SrFe_0.13Zr_0.87O_3-δcatalyst was analyzed in combination with the characterization results.It was found that the reduction treatment promoted the electron transfer in the perovskite,while generating more vacancy defects,which could promote the generation of reactive radicals during the reaction process,thus improving the ozone utilization and pollutant removal effect.In addition,the intermediate products during the reaction processes were also studied using GC-MS,and the degradation mechanism of m-cresol in CWOO was proposed.Finally,Co was introduced to prepare a bilayer perovskite Sr₂Fe_（1-x）Co_xZrO₆ catalyst.Then the reaction effects,catalyst life,and regeneration performance before and after reduction were investigated.It was found that the reduced state catalyst H-Sr₂Fe_0.4Co_0.6ZrO₆ obtained through reduction treatment showed significant improvement in catalytic activity compared to the unreduced state.The lifespan of the catalyst was investigated and it was found that the catalyst H-Sr₂Fe_0.4Co_0.6ZrO₆ maintained high catalytic activity and stability in the continuous CWOO reaction for 200 hours.After the catalyst was deactivated,the regeneration operation of oxidation+rereduction was carried out on the deactivated catalysts.The regeneration of the deactivated catalysts was achieved by the operation easily.Therefore,a simple regeneration method of perovskite catalysts is proposed in the paper.