Uniform Si‐CHA Zeolite Layers Formed by a Selective Sonication‐Assisted Deposition Method

Abstract

Discrimination against the majority: The broad size distribution of conventional near‐cubic Si‐CHA (all‐silica chabazite) zeolites impedes the formation of a close‐packed layer, which is critical for the manufacture of zeolite films by secondary growth. Although present in lower abundance, platelike Si‐CHA particles cosynthesized with near‐cubic particles were deposited selectively on an α‐Al2O3 disk to form a uniform layer.

Chemical Vapor Deposition on Chabazite (CHA) Zeolite Membranes for Effective Post-Combustion CO2 Capture

“…Both samples had a wide size distribution of ∼1−10 μm and some plate-like flakes, indicated by red arrows in Figure 1a, were also observed for CHA-L particles as similar to our previous report. 45 In addition, CHA-L and -H particle sizes were estimated by measuring the side length of the near cubic particles in the SEM images; the average sizes ± the corresponding standard deviations were estimated to be 4.6 ± 2.5 μm for CHA-L and 5.3 ± 2.6 μm for CHA-H (SI Figure S2). Despite the possible inaccuracy in estimating the particle sizes based on the SEM images, the wide size distributions of CHA-L and -H particles were evident.…”

“…First, siliceous CHA membranes were manufactured on α-Al 2 O 3 discs via conducting the secondary growth of Si-CHA seed layers. 45 Figure S7a,e) revealed that a continuous, but randomly oriented, CHA membrane (here, denoted as membrane CHA-L) was successfully synthesized by secondary growth. The SEM images in Figure 3b and SI Figure S7b−d indicated that CVD treatments up to 72 h at 200°C did not provide any noticeable change in the surface morphology as compared to membrane CHA-L (Figure 3a).…”

“…Figure 3 and SI Figure S7 support that CVD treatments did not result in any pronounced change in the membrane considering the limitations of SEM and XRD characterizations, which is in a good agreement with the very negligible weight increase after Figure S8 reveals that the thickness of membrane CHA-L was ∼2 μm, which was comparable to the CHA film thickness reported previously. 45 3.3.1. CO 2 /N 2 Separation Performance under Dry Conditions.…”

Preparation of steam-stable high-silica CHA (SSZ-13) membranes for CO2/CH4 and C2H4/C2H6 separation

“…The pore size of this kind of zeolite, together with its selective adsorption properties, makes it promising for use in membranes to separate light hydrocarbon mixtures. Previously, SSZ-13 crystals [20,21] and membranes [22,23] were synthesized using N,N,N, trimethtyl-1-adamantammonium hydroxide (TMAdaOH) as the structure-directing agent (SDA). A SSZ-13 membrane with a CO 2 /CH 4 separation selectivity of 13 was firstly reported by Kalipcilar et al [23]; the membrane was prepared on the inside of porous stainless steel supports by two hydrothermal synthesis steps.…”

Spreading-wetting method for highly reproducible tertiary growth of perfective bilayer TS-1 membranes

“…The seeded growth method relies greatly on a practical seeding route. Feasible seeding methods include dip-coating [7], rubbing [14], spin-coating [15], assembling [16], and ultrasonication method [2,17]. Sato and Nakane [18] tried the simplest dip-coating method and found it to bring highly reproducible fabrication of a high-flux NaA zeolite membrane.…”