Highly CO-Selective Mixed-Matrix membranes incorporated with Ag Nanoparticle-Impregnated MIL-101 Metal–Organic frameworks

Abstract

The significance of carbon monoxide (CO) as an invaluable starting material for chemical industries necessitates comprehensive analysis of membrane-based CO separation and recovery. In this regard, highly CO-selective mixed-matrix membranes (MMMs) based on dual carriers [Ag+ ions and Ag nanoparticle (NP)-impregnated MIL-101 (Ag@MIL-101)] were fabricated herein for CO separation. A highly adhesive comb copolymer [poly(glycidyl methacrylate-co-poly(oxyethylene methacrylate); PGMA-co-POEM; PGO] plays a pivotal role as a di-functional matrix in anchoring Ag+ ions and uniformly dispersing Ag@MIL-101 particles, resulting in excellent interfacial properties. An optimal CO-separation performance is achieved at an Ag@MIL-101 loading of 10 wt% (CO permeance of 30.7 GPU and CO/N2 selectivity of 11.8), which is superior compared to that of membranes with single Ag+ ions. This study elucidates the synergistic CO transport effect of the positively charged AgNP-impregnated MOFs and Ag+ ions through the fabricated membranes, and proposes a novel concept of “accelerated transport.” The separation mechanism behind the high CO capture property is delineated using molecular dynamic simulation through morphology and energetic analyses.