In Situ Synthesis of Cation-Free Zirconia-Supported Zeolite CHA Membranes for Efficient CO₂/CH₄ Separation

Abstract

Cation-free zirconosilicate zeolite CHA and thin zirconia-supported membranes were in situ synthesized in a fluoride-free gel for the first time. The usage of the ZrO 2 /Al 2 O 3 composite support inhibited the transportation of aluminum from the support into zeolite membranes. No fluorite source was used for the synthesis of cation-free zeolite CHA membranes, indicating the green property of the synthesis. The thickness of the membrane was only 1.0 μm. The best cation-free zeolite CHA membrane prepared by the green in situ synthesis displayed a high CO 2 permeance of 1.1 × 10 −6 mol/(m 2 s Pa) and CO 2 /CH 4 selectivity of 79 at 298 K and 0.2 MPa pressure drop for an equimolar CO 2 /CH 4 mixture.

Sustainable Gel-Less Synthesis of Sub-1-μm-Thick All-Silica CHA Zeolite Membranes for Efficient CO2 Capture

“…The subsequent processing steps are described in our previous article. 41 For comparison, Si-CHA zeolite membranes were fabricated by the gel-filled method using a fluoride-free gel. The gel composition and preparation procedure were the same as those in the above gel-less synthesis.…”

“…41 Si-CHA zeolite membranes were obtained and displayed extremely high separation performance even in the presence of water vapor. 41 The drawback of gel-filled synthesis in the two studies is the usage of large amounts of gel, resulting in environmental, energy use, and cost issues. 17,41 In this current study, we have fabricated Si-CHA zeolite membranes by a gelless method using fluoride-free gel for the first time.…”

“…41 The drawback of gel-filled synthesis in the two studies is the usage of large amounts of gel, resulting in environmental, energy use, and cost issues. 17,41 In this current study, we have fabricated Si-CHA zeolite membranes by a gelless method using fluoride-free gel for the first time. In comparison to the conventional gel-filled method, over 95% of the gel is saved by the current gel-less method.…”

High throughput screening of pure silica zeolites for CF4 capture from electronics industry gas

“…30 Notwithstanding, the number of zeolite structures continues to escalate, with the synthesis and testing of each structure consuming substantial resources. 37 Against this backdrop, high-throughput computational methods have found widespread application in studying the properties of a vast array of materials simultaneously. 38–40 Classical molecular simulations like Monte Carlo and molecular dynamics have the advantage of predicting the physical properties of a structure before experimental characterization.…”

High-Performance FAU Zeolite Membranes Derived from Nano-Seeds for Gas Separation

“…Various membrane materials, such as polymer membranes [5,6], zeolite membranes [3,7,8], metal-organic framework (MOF) membranes [9,10], mixed matrix membranes [11,12], and silicon carbide membranes [13][14][15], have been explored for separation. Among them, zeolites have become promising candidates for high-performance membranes in separation processes, catalytic membranes, and sensors considering their well-defined pore sizes, molecular sieving performance, high thermal stability, and high mechanical strength [16].…”