Constructing monolithic catalysts for activating peroxymonosulfate through regulating the surface properties of alumina pellets: Performance, identification and mechanism

The preparation of monolithic catalysts with excellent catalytic performance and stability for the continuous purification of organic wastewater remains a challenge in the field of advanced oxidation processes based on sulfate radical (SR-AOPs). In this work, a series of catalysts (AP-X/Si-Co) with macroscopic dimensions (0.5–1 mm) were prepared by regulating the surface properties of alumina spheres (AP) through pre-calcination and sodium silicate modification. Optimized surface acidity by pre-calcination and sodium silicate modification induces the formation of Co 2 AlO 4 and increase the content of Co 3+ in the octahedral coordination, which are responsible for excellent catalytic performance. Meanwhile, the Si-O-Al bond and enlarged pore size endow the catalyst with excellent structural stability and reusability. In the continuous catalytic degradation experiment, the degradation ratio of p-nitrophenol (PNP) can still approach 50% in AP-1000/Si-Co/PMS system the mass ratio of simulated wastewater to catalyst dosage reaches to 4500. This study provides a simple, reliable, and effective method for preparing monolithic catalysts for organic matter degradation.