Direct synthesis of [B,H]ZSM-5 by a solid-phase method: Al_F siting and catalytic performance in the MTP reaction

Abstract

Boron-isomorphous substituted HZSM-5, [B,H]ZSM-5 zeolite was directly synthesized by solid-phase method and the properties were characterized by XRD, FESEM, N2 adsorption/desorption, FT-IR, ICP-AES, NH3-TPD, py-FTIR, TG, GC-MS, solid MAS NMR...

Controlling the morphologies and crystal growth orientations of H-ZSM-5: their impact on the structure-diffusion-performance relationship in the methanol-to-propylene reaction

“…42 For example, more acid sites appeared in the supercage and/or intersection cavity of zeolites can relatively enhance the aromatics cycle and produce more ethene and aromatic species, whereas the acid sites siting in the 10-membered ring (10-MR) channel are more encouraging for the propagation of the alkene cycle, thus preferentially generating propylene and butene. 9,43…”

“…42 For example, more acid sites appeared in the supercage and/or intersection cavity of zeolites can relatively enhance the aromatics cycle and produce more ethene and aromatic species, whereas the acid sites siting in the 10membered ring (10-MR) channel are more encouraging for the propagation of the alkene cycle, thus preferentially generating propylene and butene. 9,43 Therefore, in order to investigate the distribution of Al F in relation to different morphologies of ZSM-5 in the MTP 10c. In order to analyze the NMR spectra in greater detail, peak fitting was conducted for each sample, as shown in Fig.…”

“…For the acidity effect, Brønsted acid sites (BASs) are considered to be the active sites for olefin production. 6 In the past few decades, modification of ZSM-5 zeolites with different elements, such as phosphorus, 7 boron 8,9 or alkaline-earth metals has been shown to successively enhance the selectivity to propylene and, simultaneously, improve catalyst lifetime. 10 For instance, Gascon et al 4 demonstrated that isolating Brønsted acid sites is crucial for selectively forming propylene, while the introduction of Lewis acid sites prevents coke formation, significantly prolonging catalyst lifetime.…”

A Nanostrips-Assemble Morphology of ZSM-5 Zeolite for Efficient Propylene Production from Methanol Conversion

“…34 Acidity is a key parameter for determining the catalytic performance of zeolite catalysts. 35,36 The NH 3 -TPD curves of four catalysts displayed the existence of two types of acid sites: weak and strong acid sides, corresponding to the desorbed ammonia below and above 300 °C, respectively (see Figure S13 in the Supporting Information). The acid amounts of samples were calculated based on the peak areas of the NH 3 -TPD curves and compiled in Table S2 in the Supporting Information.…”

Promoting Syngas to Olefins with Isolated Internal Silanols‐Enriched Al‐IDM‐1 Aluminosilicate Nanosheets

“…The acidity of Al-IDM-1 samples was first characterized. The 27 Al MAS NMR spectra of Al-IDM-1 samples (Figure S6c) with different Si/Al ratios displayed that nearly all the Al atoms were tetra-coordinated in framework. The NH 3 -TPD curves showed that two peaks decreased obviously in intensity with the Si/Al ratio increasing from 50 to 600 (Figure S2C), and the calculated total acid amount decreased from 262.3 to 17.5 μmol • g À 1 (Table S2).…”