Construction Of MOF Derived Sub-nanometer Scale Catalyst And Its Catalytic Performance

The pollution of organic pollutants to water environment has seriously harmed the ecological environment and human health,especially the discharge of dye wastewater in the environment,has attracted wide attention worldwide.Advanced Oxidation Processes（AOPs）is an effective wastewater treatment technology because it can produce active substances that can efficiently degrade organic pollutants.In recent years,Fenton-like process based on peroxmonosate（PMS）has been widely studied and recognized in the degradation of persistent organic pollutants.The defects of traditional catalysts in the process of catalysis,such as low catalytic activity,poor stability,low utilization rate of PMS,and easy metal secondary pollution,have seriously hindered their application in practical production.Single-atom catalysts have become a hotspot in the field of catalysis due to their adjustable electronic structure,excellent catalytic activity clear structure and high atomic efficiency.In this paper,nitrogen-doped carbon material synthesized by solvothermal method was used as the support,and the metal ruthenium was anchored in situ on the nitrogen-doped carbon support by secondary pyrolysis method.Finally,the atomically dispersed metal site catalyst Ru _SA-N-C with particle size of about 200 nm was synthesized.The prepared Ru _SA-N-C catalyst was applied to the degradation of organic pollutants in dye wastewater,and the following conclusions were drawn:（1）The Ru _SA-N-C material prepared in this paper showed high activity and stability in the degradation of organic pollutants through heterogeneous activated peroxmonosate（PMS）.Compared with the traditional catalyst(Ru _NP-N-C)supported with ruthenium particles,Ru _SA-N-C can effectively activate PMS to produce excess active substance（¹O₂）to degrade OrangeⅡ,and the removal efficiency of OrangeⅡcan reach 100%within 6 min.For the refractory organic compounds bisphenol A and phenol,it can also achieve complete degradation efficiency within 10 min.In multiple recycling and regeneration experiments,Ru _SA-N-C showed high stability and high recycling performance.In addition,in the metal ion leaching test after the cyclic degradation experiment,Ru ions released by Ru _SA-N-C were almost negligible,indicating that the prepared Ru _SA-N-C could effectively inhibit secondary metal contamination.（2）Free radical scavenging experiments,electron spin resonance experiments and density functional theory calculations show that singlet oxygen（¹O₂）produced at the N-coordination single Ru atom（Ru-N₄）site is a key active species for efficient and rapid degradation of pollutants.At the same time,pyridinic N,as a functional site,anchored the target pollutants in the surface region of the nitrogen-doped carbon matrix.The ultra-high catalytic activity of the single Ru atomic catalyst is mainly due to its wonderful double reaction site,which significantly reduces the migration distance of the active substances such as singlet oxygen to the organic molecules adsorbed on the nitrogen-doped carbon matrix.This work innovatively provides a promising single Ru atomic catalyst/PMS system for the application of Fenton-like reaction in water treatment.