Synthesis and Structure Determination of SCM‐15: A 3D Large Pore Zeolite with Interconnected Straight 12×12×10‐Ring Channels

Abstract

A new germanosilicate zeolite named SCM‐15 (Sinopec Composite Material No. 15), the first zeolite containing a 3‐dimensional (3D) channel system with interconnected 12‐, 12‐, and 10‐ring channels (pore sizes: 6.1×7.2, 6.1×7.4, and 5.2×5.9 Å), has been synthesized using neutral 4‐pyrrolidinopyridine as organic structure‐directing agents (OSDAs). Its structure has been determined by combining single‐crystal electron diffraction (SCED) and synchrotron powder X‐ray diffraction (SPXD) data. The unique open framework structure of SCM‐15 is related to that of FOS‐5 (BEC), ITQ‐7 (ISV), PKU‐16 (POS), ITQ‐26 (IWS), ITQ‐21, Beta polymorph B, and SU‐78B, since all these framework structures can be constructed from similar chains which are connected through shared 4‐ring or double 4‐ring (d4r) units. Based on this relation, six topologically reasonable 3D large or extra‐large pore hypothetical zeolites are predicted.

Synergistically enhance confined diffusion by continuum intersecting channels in zeolites

“…Normally, adsorption and diffusion, two primary aspects of practical multidisciplinary applications such as gas separation and heterogeneous catalysis, are considered to be mutually exclusive (i.e., rapid diffusion is generally accompanied by weak adsorption and vice versa). Here, we show that the recently synthesized 3D zeolite SCM-15 (12 × 12 × 10 ring size) ( 35 ) exhibits unique diffusional behavior compared to other channel-type zeolites ( 36 , 37 ), with a nonmutually exclusive relationship between adsorption and diffusivity. On the basis of the energy profile and the distribution of adsorption configuration, the role of continuum intersections (i.e., channels made of fused cavities) is established, and the correlation between the unique framework and diffusion behavior is analyzed.…”

Research progress on the crystal structure determination using electron diffraction

“…图 13 IDM-1 (a) [59] 和SCM-15 (b) [60] 的结构示意图(网络版 彩图) 、3D-TPE-COF [62] 、3D-TPB-COF [63] 、2D-BPTA-COF [64] 、3D-BMTA-COF [64] 等多种具有不同拓扑结构的COFs材料. 收集到的数据 [63] , TPB-COF-Me (b) [63] , TPB-COF-F (c) [63] , TPE-COF (d) [62] , 3D-BMTA-COF (e) [64] , dia-c7 COF-300 (f) [61] 的结构示意图(网络版彩图) 图 15 (a~d) ECNU-23的RED数据三维重构图; (e) 结构示 意图 [65] (网络版彩图) [66] (网络版彩图)…”

Synthesis and Post‐Synthesis Transformation of Germanosilicate Zeolites

“…[6] Ge was confirmed (i)toi nduce the formation of octameric germanate ions (precursors of d4r units), (ii)to accelerate the crystallization of zeolites containing d4rs, and (iii)tostabilize such structures. [7] Several new germanosilicate zeolites with novel structures have been synthesized since BEC (ITQ-17) [8] was first prepared two decades ago,i ncluding the recently discovered SCM-14 (SOR) [9] and SCM-15 (SOV), [10] utilising the structure-directing effect of Ge.T he structure of an umber of germanosilicates synthesized thus far consists of silica parts, for example,layers,and mostly germanium-containing building blocks.I nz eolites UTL, IWW, UOV and SAZ-1, among others,silica layers are connected by d4r mostly composed of germanium ( Figure 1). Theformation of germanosilicates,the specificity of the distribution of Ge atoms in their lattice,and their potential for post-synthesis modification to new structures are discussed here from both experimental and theoretical points of view.…”

“…Several new germanosilicate zeolites with novel structures have been synthesized since BEC (ITQ‐17) was first prepared two decades ago, including the recently discovered SCM‐14 ( SOR ) and SCM‐15 ( SOV ), utilising the structure‐directing effect of Ge. The structure of a number of germanosilicates synthesized thus far consists of silica parts, for example, layers, and mostly germanium‐containing building blocks.…”