Non-thermal ultraviolet detemplation of DD3R zeolite membranes for high-selective CO₂ separation

Pure-silica DD3R zeolite membrane has been of significant interest in CO₂ separation because of its appropriate pore size (0.36 nm × 0.44 nm) to distinguish CO₂ from other gases. However, it is challenging to remove its organic template but simultaneously minimize defects by conventional calcination at high temperature. Herein, we proposed a non-thermal ultraviolet (UV) detemplation strategy to prepare high-quality DD3R zeolite membranes for CO₂ separation. The 185/254 nm UV radiation not only excited the organic template, adamantanamine (ADA) filled in the membrane but also generated reactive oxygen species (ROSs), which caused decomposition of the template at near-ambient temperature. After being exposed in UV radiation for 4 days, the resultant membrane exhibited an ultrahigh CO₂/CH₄ selectivity of 876 as well as a good CO₂ permeance of 1.37 × 10⁻⁷ mol m⁻² s⁻¹ Pa⁻¹. The scalability of such strategy was demonstrated by a large-area hollow fiber membrane module (ca. 800 cm²), which performed a notably high CO₂/CH₄ selectivity of 170 at 4.1 MPa.