非均相钌催化高铁酸盐氧化降解苯酚
Enhanced ferrate oxidation by ruthenium nanoparticles for degradation of phenol
于永强 1何佳豪 1张静2
作者信息
- 1. 重庆大学环境与生态学院,重庆,400045
- 2. 重庆大学环境与生态学院,重庆,400045;哈尔滨工业大学环境学院,哈尔滨,150090
- 折叠
摘要
本研究开发了以ZSM-5、TiO2和CeO2为载体的非均相钌(Ru)催化剂,并检验了其催化高铁酸盐(Fe(Ⅵ))氧化苯酚的性能.随着Ru/ZSM-5、Ru/TiO2或Ru/CeO2催化剂投加量的增加,Fe(Ⅵ)氧化苯酚的伪一级反应速率常数(kobs,min-1)呈线性增长趋势.催化剂的效能主要取决于载体上钌纳米颗粒的分散情况,受钌负载量的影响不明显.虽然Ru/ZSM-5的Ru载量最低,但ZSM-5的比表面积较高,且Ru在ZSM-5表面的分散性好,使其催化效能与另外两种催化剂相当.非均相钌催化性能受pH影响很大,在pH 5.0-9.0时显著提高了苯酚的去除率.Ru的催化机理为RuⅢ被Fe(Ⅵ)氧化为RuⅦ中间体,RuⅦ具有较高活性和氧化能力,可以快速氧化苯酚,从而促进Fe(Ⅵ)氧化苯酚的速率.研究通过连续10次重复使用实验考察了 3种催化剂的稳定性,证明Ru/CeO2和Ru/TiO2的稳定性优于Ru/ZSM-5,Ru/ZSM-5稳定性下降的主要原因是ZSM-5比表面积较大,更容易吸附Fe(Ⅵ)的还原产物——氢氧化铁,从而使得Ru活性位点被氢氧化铁掩盖.
Abstract
In this study,we developed ruthenium-based(Ru-based)catalysts with ZSM-5,TiO2 and CeO2 as supports,and examined their performance for catalyzing ferrate(Fe(Ⅵ))oxidation of caffeine or phenol.With the introduction of Ru/ZSM-5,Ru/TiO2,and Ru/CeO2,the pseudo-first-order reaction rate constants(kobs,min-1)of Fe(Ⅵ)oxidation of phenol increase linearly with the dosage of each catalyst.The enhancement from each catalyst depends more on the dispersion of ruthenium nanoparticles on the supports than the loading of ruthenium.Hence,we observed comparable catalytic performance for these three catalysts with Ru/ZSM-5 having the highest dispersion,but the lowest loading of ruthenium nanoparticles.Ruthenium nanoparticles significantly increased the removal of phenol at pH 5.0-9.0,while its catalytic performance was greatly affected by pH.Ru intermediate with higher oxidation state,RuⅦ,was proved to be the major active species in ruthenium catalyzed Fe(Ⅵ)oxidation.To investigate the stability of catalysts,we used Ru/CeO2,Ru/TiO2 and Ru/ZSM-5 for ten consecutive times under same reaction conditions.It was found that the stability of Ru/CeO2 and Ru/TiO2 are better than Ru/ZSM-5,which would favor their application in pilot or engineering practice.The depressed performance of Ru/ZSM-5 may be mainly associated with masking active sites by the deposited ferric hydroxide.
关键词
钌/高铁酸盐/动力学/机理/苯酚Key words
ruthenium/ferrate/kinetics/mechanism/phenol引用本文复制引用
基金项目
国家自然科学基金(22076016)
国家自然科学基金(51878095)
中央高校基本科研业务费专项(2021CDJQY-006)
出版年
2024
NETL
NSTL
万方数据